5 Best Ways to Convert Python Time to UNIX Epoch

💡 Problem Formulation: Converting datetime objects to UNIX epoch time is a common requirement for programmers, especially when dealing with APIs or databases that store timestamps in epoch format. For example, given a Python datetime object, we want to transform it into the number of seconds since January 1, 1970, also known as UNIX epoch time.

Method 1: Using time.mktime()

This method involves converting a time-tuple in local time to seconds past the epoch. The time.mktime() function takes a struct_time (or a full 9-tuple which Python’s time module can understand) and returns the corresponding UNIX timestamp.

Here’s an example:

import time
from datetime import datetime

now = datetime.now()
tuple_time = now.timetuple()
epoch_time = time.mktime(tuple_time)

print(epoch_time)

Output:

1618825767.0

This code snippet converts the current time into a timetuple, and then time.mktime() computes the UNIX epoch timestamp from this tuple. It’s straightforward, but remember, it accounts for the local timezone.

Method 2: Using calendar.timegm()

For UTC times, calendar.timegm() is the way to go. It works similarly to time.mktime() but interprets the given time-tuple as UTC time, which can be more applicable when working with coordinated universal time.

Here’s an example:

import calendar
from datetime import datetime

now = datetime.utcnow()
tuple_time = now.timetuple()
epoch_time = calendar.timegm(tuple_time)

print(epoch_time)

Output:

1618825767

This snippet uses datetime.utcnow() to get the current UTC time and calendar.timegm() to convert it to seconds since the epoch. This method is handy when timezone neutrality is desired.

Method 3: Using datetime.timestamp()

The timestamp() method of datetime objects returns the epoch time directly, which is arguably the most straightforward method available in Python 3.3 and above.

Here’s an example:

from datetime import datetime

now = datetime.now()
epoch_time = now.timestamp()

print(epoch_time)

Output:

1618825767.123456

By calling now.timestamp(), we convert the current local time to its equivalent UNIX epoch time, including fractions of a second. This method automatically handles timezone conversions if the datetime object is timezone-aware.

Method 4: Manually Calculating Epoch Time

Manual calculation involves finding the total seconds by subtracting the datetime object from the epoch start and then converting the timedelta to seconds.

Here’s an example:

from datetime import datetime

epoch_start = datetime(1970, 1, 1)
now = datetime.now()
delta = now - epoch_start
epoch_time = delta.total_seconds()

print(epoch_time)

Output:

1618825767.123456

This method subtracts the epoch start (January 1, 1970) from the current time to yield a timedelta object, which we convert to total seconds using the total_seconds() method. This is good for understanding the underlying process, but it’s more code than necessary with modern Python versions.

Bonus One-Liner Method 5: Using time() for Current Epoch Time

If you simply need the current UNIX epoch time, Python’s time.time() gives you a one-liner solution, which is convenient and efficient.

Here’s an example:

import time

epoch_time = time.time()

print(epoch_time)

Output:

1618825767.1234567

With time.time(), you instantly get the current epoch time. This method is perfect for a quick, current timestamp, although it provides no formatting options or timezone adjustments.

Summary/Discussion

• Method 1: Using time.mktime(). Strengths: Simple and familiar for those accustomed to dealing with struct_time. Weaknesses: Local timezone specific; may not be desired in every situation.
• Method 2: Using calendar.timegm(). Strengths: UTC-based; avoids timezone issues. Weaknesses: Requires a timetuple, which can be slightly less convenient than working with datetime objects directly.
• Method 3: Using datetime.timestamp(). Strengths: Very straightforward and concise; works with timezone-aware datetimes. Weaknesses: Only available in Python 3.3 and above.
• Method 4: Manually Calculating Epoch Time. Strengths: Offers a deeper understanding of the conversion process. Weaknesses: Verbose and unnecessary when built-in methods are available.
• Bonus Method 5: Using time.time(). Strengths: Extremely convenient for grabbing the current time without the need for a datetime object. Weaknesses: Less flexible as it only returns the current time.