The datetime Module

Create, format, parse, and calculate with dates and times — the right tools for every calendar and scheduling problem.

"Dates are trickier than they look. The datetime module handles leap years, weekdays, and time arithmetic so you never have to count days manually again."

— ShurAI

Three Key Classes

date

Year, month, day.
No time information.

datetime

Date AND time together.
Most commonly used.

timedelta

A duration of time.
Used for date arithmetic.

Working with date

python

from datetime import date

# Today’s date
today = date.today()
print(today)              # 2026-03-15
print(today.year)         # 2026
print(today.month)        # 3
print(today.day)          # 15
print(today.weekday())    # 0=Mon, 1=Tue ... 6=Sun

# Create any specific date
independence = date(1947, 8, 15)
print(independence)       # 1947-08-15

Working with datetime

python

from datetime import datetime

# Current date AND time
now = datetime.now()
print(now)                # 2026-03-15 14:35:22.456789
print(now.hour)           # 14
print(now.minute)         # 35
print(now.second)         # 22

# Create a specific datetime (year, month, day, hour, minute, second)
launch = datetime(2026, 8, 15, 9, 30, 0)
print(launch)             # 2026-08-15 09:30:00

Formatting Dates — strftime

strftime = “string from time” — converts a datetime to a human-friendly string:

python

from datetime import datetime
now = datetime.now()

print(now.strftime("%d %B %Y"))        # 15 March 2026
print(now.strftime("%d/%m/%Y"))        # 15/03/2026
print(now.strftime("%I:%M %p"))        # 02:35 PM
print(now.strftime("%A, %d %B %Y"))    # Saturday, 15 March 2026

# Parse a string INTO a datetime (strptime = "string parse time")
dt = datetime.strptime("15/08/2026", "%d/%m/%Y")
print(dt)                               # 2026-08-15 00:00:00

timedelta — Date Arithmetic

python

from datetime import date, timedelta

today = date.today()
week  = timedelta(days=7)

print("Today      :", today)
print("In 7 days  :", today + week)
print("7 days ago :", today - week)

# Count days between two dates
start = date(2026, 1, 1)
end   = date(2026, 12, 31)
print("Days in 2026:", (end - start).days)  # 364

Real Example — Age Calculator

python

from datetime import date

def age_info(birth_year, birth_month, birth_day):
    """Print age and days until next birthday."""
    today    = date.today()
    birthday = date(birth_year, birth_month, birth_day)

    age = today.year - birthday.year
    if (today.month, today.day) < (birthday.month, birthday.day):
        age -= 1   # birthday hasn’t happened yet this year

    next_bday = date(today.year, birthday.month, birthday.day)
    if next_bday <= today:
        next_bday = date(today.year + 1, birthday.month, birthday.day)
    days_left = (next_bday - today).days

    print(f"Age          : {age} years old")
    print(f"Next birthday: {next_bday.strftime('%d %B %Y')} ({days_left} days away)")

age_info(2000, 8, 15)

"strftime() formats a datetime as a string. strptime() parses a string into a datetime. Learn both and you can read or write any date format the world uses."

— ShurAI

🧠 Quiz — Q1

What does date.today() return?

🧠 Quiz — Q2

What is a timedelta?

🧠 Quiz — Q3

What does now.strftime('%d/%m/%Y') do?

🧠 Quiz — Q4

What is the key difference between strftime and strptime?