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How to convert a date to Unix epoch time in Python?

Python

Quick answer

Convert a datetime to Unix epoch seconds with dt.timestamp() in Python 3, for example datetime(2024,1,1).timestamp(). Be explicit about timezone: a naive datetime is interpreted as local time, so attach tzinfo=timezone.utc first if you mean UTC. To go the other way, use datetime.fromtimestamp(ts, tz=timezone.utc).

Short answer: Call dt.timestamp() on a datetime — it returns Unix epoch seconds as a float (Python 3.3+). The catch is timezones: a naive datetime (no tzinfo) is read as local time, so if you mean UTC, attach tzinfo=timezone.utc first. Reverse it with datetime.fromtimestamp(ts, tz=timezone.utc).

Unix epoch time is the number of seconds since 1970-01-01 00:00:00 UTC. The whole subtlety in converting a date is which timezone Python assumes for a datetime that doesn't carry one.

The right way: datetime.timestamp()

from datetime import datetime, timezone
 
# UTC — be explicit, and the result is unambiguous
dt = datetime(2024, 1, 1, tzinfo=timezone.utc)
print(dt.timestamp())        # 1704067200.0

timestamp() returns a float (seconds, with microsecond precision). Wrap it in int() if you only want whole seconds:

epoch = int(dt.timestamp())  # 1704067200

The timezone trap (why your value is off by hours)

A datetime with no tzinfo is naive, and timestamp() interprets it as your machine's local time — not UTC. That is the single most common bug here:

naive = datetime(2024, 1, 1)          # no timezone attached
naive.timestamp()                     # depends on the server's local TZ!

On a machine set to UTC you'd get 1704067200.0; on one set to America/New_York (UTC-5) you'd get 1704085200.0 — a five-hour difference. If your date represents UTC, say so:

utc = datetime(2024, 1, 1, tzinfo=timezone.utc)
utc.timestamp()                       # always 1704067200.0, anywhere

Rule of thumb: make the datetime timezone-aware before converting. Naive datetimes are the reason "my epoch is off by a few hours" questions exist.

Converting back

from datetime import datetime, timezone
 
ts = 1704067200
datetime.fromtimestamp(ts, tz=timezone.utc)   # 2024-01-01 00:00:00+00:00

Pass tz=timezone.utc here too. Without it, fromtimestamp gives you a local-time datetime, reintroducing the same ambiguity on the way out.

What about time.mktime()?

You'll see mktime(dt.timetuple()) in older answers. It works, but it has two real drawbacks: it assumes local time (never UTC) and it discards sub-second precision because timetuple() drops microseconds. Prefer timestamp(). If you specifically need a UTC epoch from a struct_time, use calendar.timegm() instead of mktime():

import calendar
calendar.timegm(datetime(2024, 1, 1).utctimetuple())  # 1704067200

Current epoch, right now

For "seconds since the epoch, this instant" you don't need a datetime at all:

import time
time.time()                                   # float epoch seconds now
 
from datetime import datetime, timezone
datetime.now(timezone.utc).timestamp()        # equivalent

Related guides

Sources

Key takeaways

  • •datetime.timestamp() (Python 3.3+) returns Unix epoch seconds directly.
  • •A naive datetime is read as LOCAL time; attach tzinfo=timezone.utc first if you mean UTC.
  • •time.mktime(dt.timetuple()) also works but is local-time only and unavailable on some platforms.
  • •Reverse the conversion with datetime.fromtimestamp(ts, tz=timezone.utc).

Frequently asked questions

What is the simplest way to get a Unix timestamp in Python?

Call dt.timestamp() on a datetime object; it returns epoch seconds as a float in Python 3.3+.

Why is my epoch time off by a few hours?

A naive datetime is interpreted as local time, so the offset is your timezone. Set tzinfo=timezone.utc on the datetime before calling timestamp() to get a UTC epoch.

mktime or timestamp - which should I use?

Prefer dt.timestamp(); it is timezone-aware and cross-platform. time.mktime assumes local time and is not available everywhere.

By Mohammad Wasi

Software Engineering Leader & Technical Author · Updated September 9, 2026

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