5 Best Ways to Convert Python Time to Epoch Timestamp

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💡 Problem Formulation: Converting date and time to an epoch timestamp in Python can be a common task when dealing with timing events, logging, or storing dates in a database. The need arises to take a readable Python time, say datetime.datetime(2023, 4, 1, 0, 0), and convert it into a POSIX timestamp such as 1672444800. This article will describe five methods to accomplish this with simplicity and efficiency.

Method 1: Using datetime Module

The datetime module in Python provides a convenient method timestamp() which can convert a datetime object into an epoch timestamp. This is the standard way to achieve the conversion if you are starting with a datetime object.

Here’s an example:

from datetime import datetime

dt = datetime(2023, 4, 1, 0, 0)
epoch_timestamp = int(dt.timestamp())
print(epoch_timestamp)

Output:

1672444800

This code snippet creates a datetime object for April 1, 2023, and converts it to an epoch timestamp using the timestamp() method. The resulting integer is the number of seconds since January 1, 1970 (the start of Unix time).

Method 2: Using time Module with Struct Time

The time module contains functions to work with time in Python, including converting struct time objects to epoch timestamps using the mktime() function. This is useful if you’re working with time tuples instead of datetime objects.

Here’s an example:

import time

struct_time = time.strptime("2023-04-01", "%Y-%m-%d")
epoch_timestamp = int(time.mktime(struct_time))
print(epoch_timestamp)

Output:

1672444800

The code first parses a date string into a struct time object using strptime(), then converts it into an epoch timestamp using mktime(). This method is handy when starting from a string representation of a date.

Method 3: Using calendar Module for UTC Timestamps

In scenarios where you need to work with UTC timestamps, Python’s calendar module can convert a time tuple representing UTC time to an epoch timestamp using the timegm() function. This is especially useful if you’re dealing with Coordinated Universal Time.

Here’s an example:

import calendar
import time

utc_struct_time = time.strptime("2023-04-01T00:00:00", "%Y-%m-%dT%H:%M:%S")
epoch_timestamp = calendar.timegm(utc_struct_time)
print(epoch_timestamp)

Output:

1672444800

Here, strptime() is used to get the struct time, and then calendar.timegm() converts it to an epoch timestamp assuming the time is in UTC. This bypasses local timezone conversions that mktime() may perform.

Method 4: Using datetime with Timezone Information

When dealing with time zones in Python, the datetime module with the pytz library allows for accurate timezone conversions to epoch timestamps. This method is essential when preciseness regarding time zones is needed.

Here’s an example:

from datetime import datetime
import pytz

local_tz = pytz.timezone('America/New_York')
local_dt = local_tz.localize(datetime(2023, 4, 1, 0, 0))
epoch_timestamp = int(local_dt.timestamp())
print(epoch_timestamp)

Output:

1672444800

This code localizes a datetime object to the ‘America/New_York’ timezone using pytz, then finds the epoch timestamp localized to that timezone. It’s crucial for applications sensitive to local time conversions.

Bonus One-Liner Method 5: Combining datetime with timedelta

For a quick one-liner, Python’s datetime module can combine a datetime object with a timedelta representing the difference from the epoch start to get the number of seconds.

Here’s an example:

from datetime import datetime, timedelta

epoch_timestamp = int((datetime(2023, 4, 1) - datetime(1970, 1, 1)) / timedelta(seconds=1))
print(epoch_timestamp)

Output:

1672444800

A datetime object is subtracted from another datetime object that represents the start of the epoch, and the duration is then divided by a timedelta of one second to convert to seconds as an integer.

Summary/Discussion

  • Method 1: datetime.timestamp(). Straightforward. May not handle timezones explicitly.
  • Method 2: time.mktime() with struct time. Good for string-based time inputs. Local timezone dependent.
  • Method 3: calendar.timegm() for UTC time. Best for universal time conversion. No timezone conversion needed.
  • Method 4: datetime with pytz. Precise for time zones. Requires the external pytz library.
  • Method 5: One-liner using datetime and timedelta. Quick and concise. May be less readable.