How do I convert a date to a Unix epoch?

Choose the timezone first, then parse the date in that timezone and extract Unix seconds or milliseconds. Example: 2026-06-20 09:25 UTC is 1781947500 seconds. JavaScript: Date.UTC(2026, 5, 20, 9, 25) / 1000. Python: datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp(). Shell: date -u -d '2026-06-20 09:25:00' +%s.

What does date to epoch mean?

It means turning a readable calendar value such as 2026-06-20 09:25 UTC into the Unix timestamp for that instant. Unix seconds count from 1970-01-01 00:00:00 UTC. Unix milliseconds use the same epoch but multiply the seconds value by 1000.

Does date to epoch use UTC?

The epoch count is UTC-based, but your input date may be UTC or a local wall-clock time. A date-only input such as 2026-06-20 means midnight in whichever timezone you choose. For APIs, logs, and database storage, choose UTC unless the value is explicitly a local business time.

Why does the same date give a different epoch in different timezones?

Because a wall-clock date is not a single instant until it has a timezone. 2026-06-20 09:25 in UTC is 1781947500. The same wall-clock time in America/New_York is 1781961900, and in Asia/Tokyo it is 1781915100.

Why does my Python datetime give the wrong epoch?

Usually because the datetime is timezone-naive. Python treats a naive datetime as local time when you call .timestamp(), so a laptop and a UTC server can produce different values. Use tzinfo=timezone.utc or ZoneInfo('America/New_York') before converting.

How do I convert a date to epoch in JavaScript?

For a UTC component date, use Date.UTC(year, monthIndex, day, hour, minute) and divide by 1000 for seconds. Remember that monthIndex is zero-based: June is 5. For ISO strings, parse only strings with Z or an explicit offset, such as 2026-06-20T09:25:00Z.

Should I output epoch seconds or milliseconds?

Match the receiving system. Unix tools, Python, PHP, SQL, and many backend APIs usually expect seconds. JavaScript Date, Java currentTimeMillis-style code, browser analytics, and some event streams expect milliseconds. Put the unit in the field name: scheduledAtSeconds or scheduledAtMs.

How do I convert a date to a Unix timestamp in Excel?

If A1 is a real Excel date/time value, use =(A1 - DATE(1970,1,1)) * 86400 for Unix seconds, or multiply by 86400000 for milliseconds. Format the result cell as Number, not Date. Excel formulas are not timezone-aware, so label the intended timezone in the column header.

How do I convert a date to a Unix timestamp in Google Sheets?

Use the same serial-date formula: =(A1 - DATE(1970,1,1)) * 86400 for seconds, or multiply by 86400000 for milliseconds. Google Sheets has EPOCHTODATE for the reverse direction, but date-to-epoch is best done with the formula.

How do I handle DST when converting a local date to epoch?

Use an IANA timezone and a zone-aware API. Some wall-clock times do not exist during spring-forward, and some happen twice during fall-back. Decide whether your product should reject the ambiguous time or choose the earlier or later instant.

Is timestamp to epoch the same as date to epoch?

If the timestamp is already a 10-digit Unix integer, it is already epoch seconds. If it is a 13-digit value, it is usually epoch milliseconds. If it is a database TIMESTAMP or TIMESTAMPTZ value, extract the epoch with EXTRACT(EPOCH FROM col), UNIX_TIMESTAMP(col), or the equivalent database function.

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Date to Epoch: Convert Date or Datetime to Unix Timestamp

By unixepochtime.com editorial teamMay 19, 2026Updated July 14, 2026

To convert a date to epoch, decide what timezone the wall-clock value belongs to, parse that date as one real instant, then output Unix seconds or milliseconds. For example, 2026-06-20 09:25 UTC is 1781947500 seconds or 1781947500000 milliseconds. Date-only values mean midnight in the chosen timezone.

Date to epoch in one line

Date to epoch conversion has three moving parts: the date, the timezone, and the output unit. For a concrete baseline, 2026-06-20 09:25:00 UTC converts to 1781947500 Unix seconds, or 1781947500000 Unix milliseconds. If you get a different value, one of the inputs changed: the timezone, the date parser, or seconds-vs-milliseconds.

Input	Meaning	Unix seconds
2026-06-20 09:25 UTC	One UTC instant	1781947500
2026-06-20 09:25 America/New_York	Same wall clock, Eastern daylight time	1781961900
2026-06-20 09:25 Asia/Tokyo	Same wall clock, Japan time	1781915100
2026-06-20	Midnight at the start of the date in the chosen timezone	Depends on timezone

Date to Epoch Converter Epoch to Time Converter Unix Timestamp Formats Guide

Step 1: choose the timezone

A wall-clock date is not an instant until it has a timezone. Use UTC for APIs, logs, queues, audit rows, and cross-region systems. Use a business or user timezone only when the date represents a local calendar event, such as store hours, a billing day, a renewal cutoff, or a scheduled reminder.

Step 2: convert to Unix seconds

Unix seconds are the default for shell commands, Python, PHP, Go, SQL epoch extraction, JWT claims, and many backend APIs. They are also easier to read in logs because modern values are 10 digits.

Step 3: keep milliseconds only when required

Use milliseconds for JavaScript Date, Java currentTimeMillis-style systems, browser analytics, and APIs that show 13-digit examples. Do not switch units in the middle of your app. Convert at the boundary and name the field with the unit.

What date to epoch conversion means

A Unix timestamp is a count from 1970-01-01 00:00:00 UTC. Date-to-epoch conversion runs from a human wall-clock value to that count. The hard part is not the arithmetic; it is choosing the exact instant the human date means.

These inputs look similar but are not equivalent:

2026-06-20 means the start of that calendar date in a chosen timezone.
2026-06-20 09:25 means a local wall-clock time, but it is incomplete without a timezone.
2026-06-20T09:25:00Z is already UTC and can be converted safely.
2026-06-20T09:25:00-04:00 has an explicit offset and maps to one instant.
1781947500 is already a Unix timestamp in seconds; do not convert it again.

Unix Time to Date — the reverse-direction guide Date to Epoch Converter

Date in Unix timestamp form

When a search asks for a date in Unix timestamp form, the answer is the epoch integer for a specific boundary. "2026-06-20" by itself is not enough; you need "2026-06-20 at midnight UTC" or "2026-06-20 at midnight America/New_York."

Datetime Unix epoch

A datetime with a Z suffix, offset, or IANA timezone maps cleanly to one epoch value. A datetime with no timezone depends on the machine, database session, spreadsheet, or runtime that parses it.

Timezone is part of the input

The most common date-to-epoch bug is treating a local wall-clock value as if it were UTC. That is how a release cutoff, coupon expiry, or reporting window shifts by hours after deployment. If the source value came from a user, store the user's IANA timezone name with it. If it came from a server or API contract, make it UTC and say so in the field name or schema.

Wrong: datetime(2026, 6, 20, 9, 25).timestamp() — Python uses the host timezone
Right: datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp() — explicit UTC
Wrong: new Date('2026-06-20 09:25') — JavaScript parser falls back to local-time behavior
Right: Date.UTC(2026, 5, 20, 9, 25) — UTC components; month index 5 means June
Right: Date.parse('2026-06-20T09:25:00Z') — Z suffix pins UTC
Right for local business time: store America/New_York, not just -04:00

IANA Time Zone Database Timezone-Correct Date Formatting in JavaScript

UTC input

Use UTC when the generated Unix timestamp will move between services, logs, queues, databases, or API consumers. UTC is the comparison layer.

Local business input

Use the business timezone for reporting windows, store hours, subscription renewals, payroll cutoffs, and local calendar days. Store the IANA name so future DST rules can be applied correctly.

Seconds or milliseconds?

The output unit should be dictated by the consumer, not by preference. Seconds and milliseconds both represent the same instant, but mixing them is the fastest way to ship a date bug. The symptom is usually obvious: a date near 1970, or a date thousands of years in the future.

10 digits -> Unix seconds, such as 1781947500
13 digits -> Unix milliseconds, such as 1781947500000
16 digits -> microseconds, common in databases and event streams
19 digits -> nanoseconds, common in tracing and some high-precision systems
Field names should include the unit: startsAtSeconds, scheduledAtMs, capturedAtMicros

Milliseconds vs Seconds 10 Common Unix Timestamp Bugs

Convert a date to a Unix timestamp in JavaScript

Use Date.UTC when you already have date parts that should be interpreted as UTC. It returns milliseconds, so divide by 1000 for Unix seconds. For strings, only parse ISO 8601 with a Z suffix or explicit offset. Avoid locale-looking strings such as 06/20/2026 because different runtimes can parse them differently.

Date.UTC(2026, 5, 20, 9, 25) / 1000 // 1781947500 seconds; month index 5 = June
Date.UTC(2026, 5, 20, 9, 25) // 1781947500000 milliseconds
Math.floor(Date.parse('2026-06-20T09:25:00Z') / 1000) // ISO 8601 UTC
Math.floor(Date.parse('2026-06-20T09:25:00-04:00') / 1000) // explicit offset
Avoid: new Date('2026-06-20 09:25').getTime() / 1000 // runtime-local interpretation
Temporal when available: Temporal.ZonedDateTime.from('2026-06-20T09:25-04:00[America/New_York]').epochSeconds

For UTC date-only input, construct midnight explicitly: Date.UTC(2026, 5, 20) / 1000. For a user timezone, use Temporal or a timezone library; classic Date has no clean built-in way to turn "9:25 in America/New_York" into an instant.

MDN — Date.UTC JavaScript Date.now() Guide

Convert a date to a Unix timestamp in Python

Python's datetime.timestamp() is correct only when the datetime is timezone-aware. A naive datetime is interpreted as local time, which means the same script can output different epochs on a developer laptop, a Docker container, and a production host.

from datetime import datetime, timezone
datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp() # 1781947500.0
int(datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp()) # 1781947500
from zoneinfo import ZoneInfo
int(datetime(2026, 6, 20, 9, 25, tzinfo=ZoneInfo('America/New_York')).timestamp()) # 1781961900
Avoid: datetime(2026, 6, 20, 9, 25).timestamp() # host-local
From ISO 8601: int(datetime.fromisoformat('2026-06-20T09:25:00+00:00').timestamp())

Use ZoneInfo for real user or business timezones. Fixed offsets are acceptable for one-off timestamps, but they do not carry daylight-saving rules.

Python — datetime.timestamp

Convert a date to a Unix timestamp in PHP

PHP's time APIs default to seconds. strtotime() is convenient, but bare strings inherit the server timezone from php.ini or date_default_timezone_set(). DateTimeImmutable with DateTimeZone makes the timezone visible in the code and easier to review.

strtotime('2026-06-20 09:25:00 UTC') // 1781947500
(new DateTimeImmutable('2026-06-20 09:25:00', new DateTimeZone('UTC')))->getTimestamp()
(new DateTimeImmutable('2026-06-20T09:25:00Z'))->getTimestamp()
(new DateTimeImmutable('2026-06-20 09:25:00', new DateTimeZone('America/New_York')))->getTimestamp()
Avoid: strtotime('2026-06-20 09:25:00') // server-timezone-dependent
Sub-second input: DateTimeImmutable::createFromFormat('U.u', '1781947500.123456')

PHP — strtotime() reference

Convert a date to a Unix timestamp in Go

Go makes the timezone and unit explicit. time.Date requires a location. Unix() returns seconds, while UnixMilli(), UnixMicro(), and UnixNano() return finer units. That explicitness is useful in code review because the timezone and output unit sit in the same line.

time.Date(2026, time.June, 20, 9, 25, 0, 0, time.UTC).Unix() // 1781947500
time.Date(2026, time.June, 20, 9, 25, 0, 0, time.UTC).UnixMilli() // 1781947500000
loc, _ := time.LoadLocation("America/New_York")
time.Date(2026, time.June, 20, 9, 25, 0, 0, loc).Unix() // 1781961900
t, _ := time.Parse(time.RFC3339, "2026-06-20T09:25:00Z"); t.Unix()
Sub-second: t.UnixMicro(), t.UnixNano()

Do not ignore the error from time.LoadLocation or time.Parse in production code. The examples omit it only to keep the conversion line readable.

Go — time.Date

Convert a date to a Unix timestamp in shell (Linux / macOS)

Linux and macOS both print Unix seconds with +%s, but their parsing flags differ. GNU date on Linux uses -d. BSD date on macOS uses -j -f. Use -u for UTC, or set TZ to an IANA timezone when the input is local business time.

GNU/Linux UTC: date -u -d '2026-06-20 09:25:00' +%s // 1781947500
GNU/Linux ISO: date -u -d '2026-06-20T09:25:00Z' +%s
GNU/Linux New York: TZ=America/New_York date -d '2026-06-20 09:25:00' +%s
macOS UTC: date -j -u -f '%Y-%m-%d %H:%M:%S' '2026-06-20 09:25:00' +%s
macOS ISO: date -j -u -f '%Y-%m-%dT%H:%M:%SZ' '2026-06-20T09:25:00Z' +%s
Milliseconds in shell: multiply the seconds result by 1000, or use Python/Node for sub-second values

Linux Time Converter: Unix date Command Guide man date(1) — Linux date command reference

Convert a date to a Unix timestamp in SQL

SQL conversion depends on column type and session timezone. PostgreSQL TIMESTAMPTZ is the safest shape because it represents an instant. MySQL DATETIME has no timezone of its own, so the session time_zone setting matters. For migrations and reports, pin the timezone in the query instead of trusting a connection default.

PostgreSQL: SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ '2026-06-20 09:25:00+00')::BIGINT; // 1781947500
PostgreSQL column: SELECT EXTRACT(EPOCH FROM created_at)::BIGINT FROM events;
MySQL UTC session: SET time_zone = '+00:00'; SELECT UNIX_TIMESTAMP('2026-06-20 09:25:00');
MySQL named/local source: SELECT UNIX_TIMESTAMP(CONVERT_TZ('2026-06-20 09:25:00', 'America/New_York', '+00:00')); // requires timezone tables
SQLite: SELECT strftime('%s', '2026-06-20T09:25:00Z');
BigQuery: SELECT UNIX_SECONDS(TIMESTAMP '2026-06-20 09:25:00 UTC');
BigQuery milliseconds: SELECT UNIX_MILLIS(TIMESTAMP '2026-06-20 09:25:00 UTC');
ClickHouse: SELECT toUnixTimestamp(toDateTime('2026-06-20 09:25:00', 'UTC'));

If a database value is already a Unix integer column, do not pass it through timestamp parsing again. First confirm whether the column stores seconds, milliseconds, or microseconds.

If MySQL CONVERT_TZ returns NULL for a named timezone, the server's timezone tables are not loaded. In that case, convert the local wall-clock value in application code with an IANA-aware library, or load the MySQL timezone tables before relying on named zones.

PostgreSQL — EXTRACT and date functions How to Store Unix Timestamps in a Database

Convert a date to a Unix timestamp in Excel

Excel stores dates as serial day numbers. If A1 contains a real Excel date/time value, subtract the Excel serial value for 1970-01-01 and multiply by seconds per day. This works for imported CSV dates, manual date cells, and formulas that return dates. It does not know the timezone, so label the source timezone in your sheet.

Seconds: =(A1 - DATE(1970,1,1)) * 86400
Integer seconds: =INT((A1 - DATE(1970,1,1)) * 86400)
Milliseconds: =(A1 - DATE(1970,1,1)) * 86400000
Microseconds: =(A1 - DATE(1970,1,1)) * 86400000000
Reverse direction: =A1/86400 + DATE(1970,1,1)
Format the result as Number, not Date

Example: if A1 is 2026-06-20 09:25 and you intend that value to mean UTC, the seconds formula should give 1781947500. If it does not, check whether A1 is text rather than a real Excel date.

Microsoft — DATE function

Convert a date to a Unix timestamp in Google Sheets

Google Sheets uses date serial numbers too, so the Excel formula works. For date-to-epoch, use the formula directly. Google Sheets has EPOCHTODATE for the reverse direction, but the date-to-epoch path is still serial-date math.

Seconds: =(A1 - DATE(1970,1,1)) * 86400
Integer seconds: =INT((A1 - DATE(1970,1,1)) * 86400)
Milliseconds: =(A1 - DATE(1970,1,1)) * 86400000
Microseconds: =(A1 - DATE(1970,1,1)) * 86400000000
If A1 is text, parse it first with DATEVALUE / TIMEVALUE or import it as a date column
Check File -> Settings -> Time zone before using NOW(), TODAY(), or locally entered date/time values

For the reverse task, Google documents EPOCHTODATE(timestamp, unit), where unit 1 is seconds, 2 is milliseconds, and 3 is microseconds.

Google Sheets EPOCHTODATE documentation Google Sheets DATE function

Wall-clock to instant: DST gap and overlap handling

Going from a local wall-clock time to a Unix timestamp is the genuinely hard direction. Most local times map to one instant. Around daylight-saving transitions, some local times map to zero instants and some map to two. If your product schedules reminders, renewals, cron-like jobs, or local cutoffs, choose and document a policy.

Spring-forward gap: a wall-clock value that does not exist, such as 2026-03-08 02:30 in America/New_York.
Fall-back overlap: a wall-clock value that happens twice, such as 2026-11-01 01:30 in America/New_York.
Earlier overlap example: 2026-11-01T01:30:00-04:00 -> 1793511000.
Later overlap example: 2026-11-01T01:30:00-05:00 -> 1793514600.
Product policy: reject impossible times, or choose earlier/later explicitly.
Storage policy: store the UTC epoch plus the IANA timezone when the local meaning matters later.

10 Common Unix Timestamp Bugs The Year 2038 Problem Timezone Converter

Pre-store checklist

Before storing the result, verify the source timezone, output unit, DST behavior, and field name. This is the small checklist that catches the bugs that only appear after deployment on a different server.

Quick reference: date to epoch by tool

Use this section when you already know the input timezone and just need the right syntax. The examples all use 2026-06-20 09:25 UTC and return 1781947500 seconds unless noted.

Tool	Unix seconds example	Notes
JavaScript	Date.UTC(2026, 5, 20, 9, 25) / 1000	Month index is zero-based
Python	int(datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp())	Never use naive datetime
PHP	strtotime('2026-06-20 09:25:00 UTC')	Prefer DateTimeImmutable for app code
Go	time.Date(2026, time.June, 20, 9, 25, 0, 0, time.UTC).Unix()	Location is explicit
Linux shell	date -u -d '2026-06-20 09:25:00' +%s	GNU date
macOS shell	date -j -u -f '%Y-%m-%d %H:%M:%S' '2026-06-20 09:25:00' +%s	BSD date
PostgreSQL	EXTRACT(EPOCH FROM TIMESTAMPTZ '2026-06-20 09:25:00+00')::BIGINT	Prefer TIMESTAMPTZ
MySQL	SET time_zone = '+00:00'; SELECT UNIX_TIMESTAMP('2026-06-20 09:25:00');	Session timezone matters
Excel	=(A1 - DATE(1970,1,1)) * 86400	A1 must be a real date cell
Google Sheets	=(A1 - DATE(1970,1,1)) * 86400	Check sheet timezone for entered dates

Current Unix Timestamp in Code Epoch Converter Guide

FAQ

How do I convert a date to a Unix epoch?: Choose the timezone first, then parse the date in that timezone and extract Unix seconds or milliseconds. Example: 2026-06-20 09:25 UTC is 1781947500 seconds. JavaScript: Date.UTC(2026, 5, 20, 9, 25) / 1000. Python: datetime(2026, 6, 20, 9, 25, tzinfo=timezone.utc).timestamp(). Shell: date -u -d '2026-06-20 09:25:00' +%s.
What does date to epoch mean?: It means turning a readable calendar value such as 2026-06-20 09:25 UTC into the Unix timestamp for that instant. Unix seconds count from 1970-01-01 00:00:00 UTC. Unix milliseconds use the same epoch but multiply the seconds value by 1000.
Does date to epoch use UTC?: The epoch count is UTC-based, but your input date may be UTC or a local wall-clock time. A date-only input such as 2026-06-20 means midnight in whichever timezone you choose. For APIs, logs, and database storage, choose UTC unless the value is explicitly a local business time.
Why does the same date give a different epoch in different timezones?: Because a wall-clock date is not a single instant until it has a timezone. 2026-06-20 09:25 in UTC is 1781947500. The same wall-clock time in America/New_York is 1781961900, and in Asia/Tokyo it is 1781915100.
Why does my Python datetime give the wrong epoch?: Usually because the datetime is timezone-naive. Python treats a naive datetime as local time when you call .timestamp(), so a laptop and a UTC server can produce different values. Use tzinfo=timezone.utc or ZoneInfo('America/New_York') before converting.
How do I convert a date to epoch in JavaScript?: For a UTC component date, use Date.UTC(year, monthIndex, day, hour, minute) and divide by 1000 for seconds. Remember that monthIndex is zero-based: June is 5. For ISO strings, parse only strings with Z or an explicit offset, such as 2026-06-20T09:25:00Z.
Should I output epoch seconds or milliseconds?: Match the receiving system. Unix tools, Python, PHP, SQL, and many backend APIs usually expect seconds. JavaScript Date, Java currentTimeMillis-style code, browser analytics, and some event streams expect milliseconds. Put the unit in the field name: scheduledAtSeconds or scheduledAtMs.
How do I convert a date to a Unix timestamp in Excel?: If A1 is a real Excel date/time value, use =(A1 - DATE(1970,1,1)) * 86400 for Unix seconds, or multiply by 86400000 for milliseconds. Format the result cell as Number, not Date. Excel formulas are not timezone-aware, so label the intended timezone in the column header.
How do I convert a date to a Unix timestamp in Google Sheets?: Use the same serial-date formula: =(A1 - DATE(1970,1,1)) * 86400 for seconds, or multiply by 86400000 for milliseconds. Google Sheets has EPOCHTODATE for the reverse direction, but date-to-epoch is best done with the formula.
How do I handle DST when converting a local date to epoch?: Use an IANA timezone and a zone-aware API. Some wall-clock times do not exist during spring-forward, and some happen twice during fall-back. Decide whether your product should reject the ambiguous time or choose the earlier or later instant.
Is timestamp to epoch the same as date to epoch?: If the timestamp is already a 10-digit Unix integer, it is already epoch seconds. If it is a 13-digit value, it is usually epoch milliseconds. If it is a database TIMESTAMP or TIMESTAMPTZ value, extract the epoch with EXTRACT(EPOCH FROM col), UNIX_TIMESTAMP(col), or the equivalent database function.