datetime-module.md

id	datetime-module
slug	/datetime-module
title	Datetime Module
description	Working with dates and times in Python using the datetime module — parsing, formatting, arithmetic, and timezone handling compared to JavaScript's Date.
sidebar_label	Datetime Module

The datetime module in Python provides classes and functions for handling dates, times, and time intervals.

Task

Design a program to calculate Xiao Ming's age and the number of days until his next birthday. Xiao Ming's birthday is on January 15, 1992.

JavaScript implementation

// Get the current date
const currentDate = new Date();

// Set Xiao Ming's birthday
const birthday = new Date(1992, 0, 15);

// Calculate age
let age = currentDate.getFullYear() - birthday.getFullYear();

// Check if the birthday has passed this year
if (currentDate.getMonth() < birthday.getMonth() || (currentDate.getMonth() === birthday.getMonth() && currentDate.getDate() < birthday.getDate())) {
  age--;
}

// Calculate the number of days until the next birthday
const nextBirthday = new Date(currentDate.getFullYear(), birthday.getMonth(), birthday.getDate());
if (currentDate > nextBirthday) {
  nextBirthday.setFullYear(nextBirthday.getFullYear() + 1);
}

const daysUntilNextBirthday = Math.ceil((nextBirthday - currentDate) / (1000 * 60 * 60 * 24));

// Output the results
console.log("Age: " + age);
console.log("Days until next birthday: " + daysUntilNextBirthday);

Python implementation

import datetime

# Get the current date
current_date = datetime.date.today()

# Set Xiao Ming's birthday
birthday = datetime.date(1992, 1, 15)

# Calculate age
age = current_date.year - birthday.year
if current_date.month < birthday.month or (current_date.month == birthday.month and current_date.day < birthday.day):
    age -= 1

# Calculate the number of days until the next birthday
next_birthday = datetime.date(current_date.year, birthday.month, birthday.day)
if current_date > next_birthday:
    next_birthday = datetime.date(current_date.year + 1, birthday.month, birthday.day)

days_until_next_birthday = (next_birthday - current_date).days

# Output the results
print("Age:", age)
print("Days until next birthday:", days_until_next_birthday)

Code Highlight

• In Python, use date from the datetime module to manipulate dates, while JavaScript uses Date.
• In Python, you can directly use the + and - arithmetic operators to perform calculations with dates.

Difference Quick View

Feature	JavaScript	Python
Create DateTime object	new Date(1992, 0, 15)	datetime.datetime(1992, 1, 15)
Current local DateTime	new Date()	datetime.datetime.now()
Current UTC DateTime	new Date().toUTCString()	datetime.datetime.utcnow()
Date formatting	moment(myDateTime).format(format)	my_datetime.strftime(format)
Get year, month, day	myDateTime.getFullYear() myDateTime.getMonth() + 1 myDateTime.getDate()	my_datetime.year my_datetime.month my_datetime.day
Get hour, minute, second	myDateTime.getHours() myDateTime.getMinutes() myDateTime.getSeconds()	my_datetime.hour my_datetime.minute my_datetime.second
Add time interval	myDateTime.setSeconds(date.getSeconds() + secondsToAdd)	new_datetime = my_datetime + timedelta(seconds=secondsToAdd)
Subtract time interval	myDateTime.setSeconds(date.getSeconds() - secondsToSubtract)	new_datetime = my_datetime - timedelta(seconds=secondsToSubtract)
Compare dates	dateTime1.getTime() - dateTime2.getTime()	datetime1 - datetime2

:::tip timedelta If basic date and time operations are not sufficient for your needs, you can use timedelta, a class that represents a duration or difference between two dates or times. It can be used to perform arithmetic with dates and times, as well as calculate time differences.

from datetime import timedelta, datetime
current_datetime = datetime.now()

# Get the datetime 2 days, 3 hours, and 30 minutes from now
new_datetime = current_datetime + timedelta(days=2, hours=3, minutes=30)
print(new_datetime)

:::

Resources

• Python datetime module documentation