How to get the seconds since epoch from the time + date output of gmtime()?

python

prompt-engineering

datetime

timestamp

byNikita Barsukov·Aug 28, 2024

Let's get down to business. To convert UTC time provided by gmtime() to seconds since the epoch, you can employ the calendar.timegm():

import calendar
import time

# Time flies like an arrow; fruit flies like a banana
# So, let's capture that elusive time arrow in epoch seconds
epoch_seconds = calendar.timegm(time.gmtime())
print(epoch_seconds)

Voila! There you have the epoch timestamp in UTC, thus skirting any time zone mishaps you'd encounter with mktime(), which anticipates local time.

Precise parsing // when regex isn't enough

Are you dealing with a UTC date and time string and need to convert that to epoch seconds? Fear not. We've got calendar.timegm() and time.strptime() to the rescue:

import calendar
import time

# everytime you try to parse date without a library, a kitten dies, so let's save kittens
utc_time_string = 'Apr 10, 2023 @ 15:30:00 UTC'
pattern = '%b %d, %Y @ %H:%M:%S UTC'

# Strptime's like a time machine fuel. It won't run without proper formula
time_tuple = time.strptime(utc_time_string, pattern)
# And here we go, back...back...back to the future
epoch_seconds = calendar.timegm(time_tuple)

print(f"Seconds since epoch: {epoch_seconds}")

Remember, strptime() needs a format string accurate enough to parse the date and time with surgical precision. Meanwhile, calendar.timegm() ensures the conversion to epoch is strictly UTC-based.

Datetime parse-fection // the fun way around dates

Invalid dates running circles around your head? Enter datetime.strptime() and timestamp() from the datetime module. You know how people say "There is no time like the present", well...

from datetime import datetime

utc_datetime_string = 'Apr 10, 2023 @ 15:30:00 UTC'
pattern = "%b %d, %Y @ %H:%M:%S %Z"

# When life gives you strings, make datetime objects!
date_time_obj = datetime.strptime(utc_datetime_string, pattern)
# Then squeeze out the seconds
epoch_seconds = int(date_time_obj.timestamp())

print(epoch_seconds)

Now hold your horses, datetime.timestamp() gives you a floating-point number, which we've cast to an integer using int() for consistency.

Pro tips // wisdom from the ancients

Now before you start pivoting your log files to determine what your cat does with your keyboard at 3 AM, keep these considerations in mind:

Leap seconds: They're like the 'unbirthdays' in 'Alice in Wonderland'. Neither time nor datetime modules are fans of surprise parties, so they don't account for them.
Locale-dependent functions: locale.setlocale() and time.mktime() are like chameleons, prone to change colors based on their surroundings, leading to errors.

Timezone tangle // from doom to datetime

You got timezones to work with? No problem, the datetime module is cool with timezone-aware objects:

from datetime import datetime, timezone

date_time_utc = datetime.now(timezone.utc)
# As the Stark motto goes, "Secs is coming"
epoch_seconds = int(date_time_utc.timestamp())

print(epoch_seconds)

History 101 // those who forget past times are doomed to overfit

Got historical dates to handle? Ensure your approach accounts for 'Back to the Future' moments like daylight saving time or leap seconds, as applicable.