Datetime Format in Python - How to Convert from Unix Time and String

Python datetime module is a powerful tool for working with dates and times. It provides a range of functions and classes to manipulate, format, and parse dates and times in various formats. With Python datetime, you can easily perform arithmetic operations on dates and times, convert between different time zones, and much more. Whether you're working with timestamps, calendars, or scheduling tasks, datetime can help make your Python code more robust and flexible.

Datetime Formats in Python

Python's built-in datetime module serves for working with dates and times. Here are some common datetime formats in Python:

YYYY-MM-DD : Year, month, and day separated by hyphens.
YYYY/MM/DD : Year, month, and day separated by slashes.
MM/DD/YYYY : Month, day, and year separated by slashes.
DD-MM-YYYY : Day, month, and year separated by hyphens.
DD/MM/YYYY : Day, month, and year separated by slashes.
YYYY-MM-DD HH:MM:SS : Year, month, and day separated by hyphens, followed by hours, minutes, and seconds separated by colons.
YYYY-MM-DD HH:MM:SS.mmmmmm : Year, month, and day separated by hyphens, followed by hours, minutes, and seconds separated by colons, and microseconds separated by a dot.

Date & Time Formatting in Python

In Python, you can format dates and times as a string using the strftime() method of a datetime object. This method allows you to specify a format string that defines how the date or time should be formatted.

Here is a list of some commonly used date and time formats in Python:

%Y: year (4 digits)
%m: month (zero-padded)
%d: day of the month (zero-padded)
%H: hour (24-hour clock)
%M: minute (zero-padded)
%S: second (zero-padded)

How to Get Current Date & Time from Datetime Object in Python

To extract the current date from a datetime object in Python, you can use the date() method. Here's an example of how to convert a datetime object to a date object by accessing the date() method of the datetime object:

from datetime import datetime

current_datetime = datetime.now()
current_date = current_datetime.date()

print(current_date)

This code will output the current date in the format YYYY-MM-DD. For example, if you run the code today (May 17, 2023), the output will be 2023-05-17.

Here's also an example of getting the current date and time:

from datetime import datetime

# Get the current date and time
current_datetime = datetime.now()

print(current_datetime)  # Output: Current date and time in the format YYYY-MM-DD

How to Get Current Year from a Datetime Object

To extract the year from a datetime object in Python, you can use the year attribute. Here's an example:

from datetime import datetime

# Create a datetime object
dt = datetime(2023, 5, 17, 12, 34, 56)

# Extract the year from the datetime object
year = dt.year

print(year) # Output: 2023

AM/PM Datetime Format in Python

In Python's datetime module, you can format a datetime object to display the time in AM/PM format using the %I and %p directives in the strftime method. Here's an example:

from datetime import datetime

# Get the current datetime
now = datetime.now()

# Format the time in AM/PM format
formatted_time = now.strftime("%I:%M %p")

# Print the formatted time
print(formatted_time)

This code will output the current time in the format "hh:mm AM/PM". For example, if the current time is 2:30 PM, the output will be "02:30 PM".

Clock Time Format

In Python, you can retrieve the current time in a "clock time" format using the datetime module. Here's an example:

from datetime import datetime

# Get the current time
current_time = datetime.now().time()

# Format the time as a clock time
clock_time = current_time.strftime("%H:%M:%S")

print("Current Clock Time:", clock_time) # Output: Current Clock Time: 12:34:56

The strftime() method is used to format the time as a clock time string. The format code %H represents the hour (24-hour clock), %M represents the minute, and %S represents the second.

By applying the strftime() method with the appropriate format code, you can obtain the current time in a clock time format.

A Way to Convert Datetime to String in Python

To convert a Python datetime object to a string, you can use the strftime() method. The strftime() method takes a format string as an argument and returns a string representation of the datetime object according to the specified format.

Here's an example of how to format the current date and time:

import datetime

now = datetime.datetime.now()  # Get the current datetime object
formatted_date = now.strftime("%Y-%m-%d %H:%M:%S")  # Format the datetime object
print(formatted_date)  # Print the formatted datetime string

The String to Datetime Conversion

You can use the datetime module in Python to convert a string to a datetime object in Python. Here's an example of string to time conversion:

from datetime import datetime

# define the format of the input string
input_format = '%Y-%m-%d %H:%M:%S'

# input string
input_string = '2022-05-14 10:30:00'

# convert the input string to a datetime object
dt_object = datetime.strptime(input_string, input_format)

# print the datetime object
print(dt_object)

In this example, we use the Python's datetime.strptime() method for converting the input string to a datetime object. The strptime() method takes two arguments: the input string and the format of the input string. The format string uses various format codes to specify the format of the input string. In this case, the format code %Y represents the year, %m represents the month, %d represents the day, %H represents the hour, %M represents the minute, and %S represents the second.

The dt_object variable now contains a datetime object that represents the date and time in the input string. You can then perform various operations on the datetime object, such as formatting it in a different way or performing arithmetic operations on it.

The same algorithm can be used to convert a string to a date object.

Let's look at the examle of string to date object converting in Python:

from datetime import datetime

date_string = "2023-05-22"

# Convert string to date object
my_date = datetime.strptime(date_string, "%Y-%m-%d").date()

print(my_date)  # Output: 2023-05-22

The datetime.now() and datetime.today() Methods

In Python, you can use the built-in datetime module to work with date and time values. To get the current date and time, you can use the datetime.now() method.

In the following example first we get date and time and then print it:

from datetime import datetime

now = datetime.now()
print("Current date and time:", now)

This will output the current date and time in the format YYYY-MM-DD HH:MM:SS.ssssss.

There is one more way to get the current date and time, you can use the datetime.today() method. Here's an example:

import datetime

now = datetime.datetime.today()
print(now) # This will output the current date and time in the format YYYY-MM-DD HH:MM:SS.mmmmmm.

If you want to display only the current time without the date, you can use the strftime() method to format the output before printing:

import datetime
current_time = datetime.datetime.now().strftime("%H:%M:%S")
print("Current time:", current_time)

This will output the current time in the format HH:MM:SS.

How to Extract the Date from a datetime Object

In Python, you can extract the date portion from a datetime object using the .date() method. Here's an example:

import datetime

# create a datetime object
dt = datetime.datetime(2023, 5, 14, 10, 30, 0)

# extract the date portion
date = dt.date()

# print the date
print(date)  # output: 2023-05-14

Datetime to Epoch Conversion

You can convert a Python datetime object to epoch time (i.e., the number of seconds since January 1, 1970, 00:00:00 UTC) using the timestamp() method. Let's look at the example how to convert a Python datetime object to a timestam:

import datetime

# Create a datetime object for May 14, 2023 at 12:34:56 UTC
dt = datetime.datetime(2023, 5, 14, 12, 34, 56)

# Convert the datetime object to epoch time
epoch_time = int(dt.timestamp())

print(epoch_time)  # Output: 1687877696

Epoch to Datetime Conversion

You can convert a Unix epoch time (i.e., the number of seconds since January 1, 1970, 00:00:00 UTC) to a Python datetime object using the datetime.fromtimestamp() method.

Here's an example of how to convert Unix time to datetime in Python:

import datetime

# Unix epoch time for May 14, 2023 at 12:34:56 UTC
epoch_time = 1687877696

# Convert the epoch time to a datetime object
dt = datetime.datetime.fromtimestamp(epoch_time)

print(dt)  # Output: 2023-05-14 12:34:56

If you want to convert a timestamp to a datetime object in a specific timezone in Python, you can use libraries like pytz or dateutil to set the desired timezone.

Parsing into a datetime Module

To parse a date or time string into a datetime object, you can use the datetime.datetime.strptime() method.

The strptime() method takes two arguments: the string you want to parse, and a format string that specifies the format of the input string. The format string uses special codes to represent different parts of the date and time, such as %Y for the year, %m for the month, %d for the day, %H for the hour, %M for the minute, and %S for the second.

Here's an example of how to parse a date string in the format "YYYY-MM-DD":

import datetime

date_string = "2023-05-14"
date_object = datetime.datetime.strptime(date_string, "%Y-%m-%d")

print(date_object)

Timezones and DateTime Module in Python

You can use the datetime module to work with dates, times, and timezones in Python.

To work with timezones, you need to use the pytz library. This library provides a comprehensive database of timezones and tools for working with them.

Here's an example of how you can work with timezones using the datetime module and pytz library in Python:

import datetime
import pytz

# create a datetime object in UTC timezone
utc_datetime = datetime.datetime.now(tz=pytz.utc)
print("UTC datetime:", utc_datetime)

# convert the datetime object to a different timezone
local_timezone = pytz.timezone('America/New_York')
local_datetime = utc_datetime.astimezone(local_timezone)
print("Local datetime:", local_datetime)

In this example, we first create a datetime object in the UTC timezone using the datetime.datetime.now() method and passing in the pytz.utc timezone object as the tz parameter. We then print out the UTC datetime.

Next, we create a pytz.timezone object representing the local timezone (America/New_York), and then use the astimezone() method to convert the UTC datetime object to the local timezone. Finally, we print out the local datetime.

DateTime Module and Timedelta Class

The datetime module in Python provides various classes for working with dates, times, and time intervals. One of the classes available in the module is timedelta, which represents a duration or difference between two dates or times.

Here's an example of how to use timedelta:

import datetime

# create a datetime object for the current time
now = datetime.datetime.now()

# create a timedelta object representing a duration of 1 day
one_day = datetime.timedelta(days=1)

# calculate a new datetime object that is 1 day in the future
tomorrow = now + one_day

# print the result
print(tomorrow)

Here's also an example of how to find time delta or time difference in Python:

import datetime

# create two datetime objects
start_time = datetime.datetime(2023, 5, 15, 10, 30, 0)
end_time = datetime.datetime(2023, 5, 15, 14, 45, 0)

# calculate the time difference
delta = end_time - start_time

# print the result
print(delta)  # prints: 4:15:00

This way you can measure execution time of any code snippet.

To calculate time difference in seconds, you can use the total_seconds() method.

The timedelta class provides several other arguments that can be used to specify different units of time, including weeks, hours, minutes, seconds, microseconds, and milliseconds.

How to Compare Datetime Objects

In Python, you can compare datetime objects using the comparison operators (<, >, <=, >=, ==, !=).

Let's look at the example of how to compare dates in Python:

from datetime import datetime

# create datetime objects
date1 = datetime(2021, 9, 1)
date2 = datetime(2021, 9, 2)

# compare datetime objects
if date1 < date2:
    print("date1 is before date2")
else:
    print("date1 is after date2")

As a result of comparing dates we get "date1 is before date2".

You can also compare datetime objects with date objects. In that case, the date object is treated as if it has a time of midnight. For example:

from datetime import datetime, date

# create datetime and date objects
date1 = datetime(2021, 9, 1, 10, 30)
date2 = date(2021, 9, 2)

# compare datetime and date objects
if date1 < date2:
    print("date1 is before date2")
else:
    print("date1 is after date2")

How to Add Days to a Datetime Object

To add time to a Python datetime object, you can use the timedelta class from the datetime module.

Here's an example code snippet that shows how to add 3 days to the current date:

from datetime import datetime, timedelta

current_date = datetime.now()
print("Current date:", current_date)

new_date = current_date + timedelta(days=3)
print("New date:", new_date)

You can adjust the number of days to add by changing the value of the days argument when creating the timedelta object.

Datetime Module and isoformat() Method in Python

The isoformat() method is used to get the string representation of a date or time object in ISO 8601 format. Here's an example:

import datetime

# create a datetime object for May 14, 2023 at 2:30 PM
dt = datetime.datetime(2023, 5, 14, 14, 30)

# get the ISO 8601 string representation of the datetime object
iso_str = dt.isoformat()

print(iso_str)  # output: 2023-05-14T14:30:00

In the ISO 8601 format, the date and time are separated by the letter "T", and the time is given in 24-hour format. The string representation of the datetime object obtained using isoformat() method does not include timezone information. If you need to include timezone information, you can use the strftime() method with an appropriate format string.

The datetime.utcnow() Method

In Python, the datetime module provides a method called datetime.utcnow() that returns the current date and time as a datetime object in UTC (Coordinated Universal Time).

Here's an example:

import datetime

now_utc = datetime.datetime.utcnow()
print(now_utc)

This will output the current UTC date and time in the format YYYY-MM-DD HH:MM:SS.mmmmmm.

It's worth noting that datetime.utcnow() returns the current UTC time, which does not take into account any time zone offset. If you want to convert this time to a local time zone, you'll need to use the datetime.astimezone() method.

How to Print a Datetime Object in Python

To print a datetime object in a specific format in Python, you can use the strftime() method from the datetime module. This method allows you to format a datetime object into a string representation.

Here's an example of printing a datetime object in a specific format:

from datetime import datetime

# Create a datetime object
dt = datetime(2023, 5, 17, 12, 34, 56)

# Format and print the datetime object
formatted_datetime = dt.strftime("%Y-%m-%d %H:%M:%S")
print(formatted_datetime)

In this example, we create a datetime object dt representing a specific date and time. Then, we use the strftime() method to format it as a string. The format string "%Y-%m-%d %H:%M:%S" specifies the desired format for the datetime string. %Y represents the year with four digits, %m represents the month with zero-padding, %d represents the day with zero-padding, %H represents the hour in 24-hour format, %M represents the minute, and %S represents the second.

The output will be the formatted datetime string:

2023-05-17 12:34:56

You can customize the format string based on your specific requirements. For more details about the format codes for strftime(), you can refer to the Python documentation: strftime() and strptime() Format Codes.

Date Class of the Datetime Module

The datetime module provides the date class, which allows you to work specifically with dates (without considering time). Here's an example of how to use the date class:

from datetime import date

# Create a date object for May 22, 2023
my_date = date(2023, 5, 22)

# Get individual components of the date
year = my_date.year
month = my_date.month
day = my_date.day

print(year, month, day)  # Output: 2023 5 22