Python Date and Time

The manipulation of dates is one of the most common things in Python, whether it’s data analysis, automating tasks, or just work with time-sensitive information. Python has a lot of tools and libraries that support date and time, with the most commonly used module being the datetime module.

1. The `datetime` Module

The datetime module provides classes for manipulating dates and times. Here are the main classes in this module:

date: Handles dates (year, month, day).
time: Time. Handles times (hours, minutes, seconds, microseconds).
datetime: Combines date and time information.
timedelta: A duration, or the difference between two dates or times.

2. Working with Dates

Creating a Date Object

The date class allows you to create and manipulate dates.

from datetime import date

# Create a date object
d = date(2024, 12, 21) # Year, Month, Day
print(d) # Output: 2024-12-21

Getting Today’s Date

You can use date.today() to get the current date.

from datetime import date

today = date.today()
print(today) # Output: Current date (e.g., 2024-12-21)

Accessing Date Components

You can access the year, month, and day using attributes.

print(today.year) # Output: 2024
print(today.month) # Output: 12
print(today.day) # Output: 21

3. Formatting Dates

The strftime() method formats a date object into a string.

formatted_date = today.strftime("%B %d, %Y") # Full month name, day, year
print(formatted_date) # Output: December 21, 2024

Common Format Codes:

%Y: Year. Example: 2024
%m: Month in zero-padding. Example: 12
%B: Full month name. Example: December
%d: Day of the month. Example: 21

4. Parsing Dates

The strptime() method parses a string into a date or datetime object.

from datetime import datetime

date_string = "2024-12-21"
parsed_date = datetime.strptime(date_string, "%Y-%m-%d").date()
print(parsed_date) # Output: 2024-12-21

5. Date Arithmetic

Using the timedelta class, you can perform operations like adding or subtracting days.

from datetime import timedelta

# Add 10 days
future_date = today + timedelta(days=10)
print(future_date) # Output: 2024-12-31

# Subtract 10 days
past_date = today - timedelta(days=10)
print(past_date) # Output: 2024-12-11

6. Combining Date and Time

The datetime class combines both date and time.

from datetime import datetime

# Create a datetime object
dt = datetime(2024, 12, 21, 14, 30, 0) # Year, Month, Day, Hour, Minute, Second
print(dt) # Output: 2024-12-21 14:30:00

You can also get the current date and time using datetime.now().

current_datetime = datetime.now()
print(current_datetime) # Output: Current date and time

7. Practical Examples

Calculate the Difference Between Two Dates

date1 = date(2024, 12, 21)
date2 = date(2025, 1, 1)

difference = date2 - date1
print(difference.days) # Output: 11

Check for a Leap Year

def is_leap_year(year):
   return (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)

print(is_leap_year(2024)) # Output: True
print(is_leap_year(2023)) # Output: False

8. Additional Libraries

time module: Supplies the lower-level time functionality.
calendar module: Provides specific calendar functions, such as determining weekdays or leap years.
pytz library (third-party): For handling time zones.
dateutil library (third-party): For advanced date manipulation and parsing.

Key Takeaways

The datetime module is a versatile module that supports many common date operations.
Use strftime() and strptime() for formatting and parsing dates.
For time zones and further functionality, third-party libraries like pytz or dateutil come into play.