Skip to main content

​
Python Date Operations

Working with dates in Python is straightforward with the datetime module. These utilities simplify common date operations like calculating differences, adding days, and checking date properties.

​
Calculate Date Differences

Calculate the difference between two dates in days, months, or years: 
from datetime import date
from math import ceil

def days_diff(start, end):
  return (end - start).days

def months_diff(start, end):
  return ceil((end - start).days / 30)

def years_diff(start, end):
  return ceil((end - start).days / 365)

days_diff(date(2020, 10, 25), date(2020, 10, 28)) # 3
months_diff(date(2020, 10, 25), date(2020, 11, 25)) # 1
years_diff(date(2020, 10, 25), date(2021, 10, 25)) # 1

​
Calculate Relative Dates

​
Days Ago

Calculate a date n days in the past: 
from datetime import timedelta, date

def days_ago(n):
  return date.today() - timedelta(n)

days_ago(5) # date(2020, 10, 23)

​
Days From Now

Calculate a date n days in the future: 
from datetime import timedelta, date

def days_from_now(n):
  return date.today() + timedelta(n)

days_from_now(5) # date(2020, 11, 02)

​
Add Days to a Date

Add days to any date: 
from datetime import date, datetime, timedelta

def add_days(n, d = datetime.today()):
  return d + timedelta(n)

add_days(5, date(2020, 10, 25)) # date(2020, 10, 30)
add_days(-5, date(2020, 10, 25)) # date(2020, 10, 20)

​
Subtract Days from a Date

Subtract days from any date: 
from datetime import date, datetime, timedelta

def subtract_days(n, d = datetime.today()):
  return d - timedelta(n)

subtract_days(5, date(2020, 10, 25)) # date(2020, 10, 20)
subtract_days(-5, date(2020, 10, 25)) # date(2020, 10, 30)

​
Check Date Properties

​
Check if Date is Weekend

from datetime import datetime, date

def is_weekend(d = datetime.today()):
  return d.weekday() > 4

is_weekend(date(2020, 10, 25)) # True
is_weekend(date(2020, 10, 28)) # False

​
Check if Date is Weekday

from datetime import datetime, date

def is_weekday(d = datetime.today()):
  return d.weekday() <= 4

is_weekday(date(2020, 10, 25)) # False
is_weekday(date(2020, 10, 28)) # True

​
Practical Use Cases

​
Calculate Age

from datetime import date

def calculate_age(birth_date):
  today = date.today()
  return years_diff(birth_date, today)

birth_date = date(1990, 5, 15)
age = calculate_age(birth_date)  # Current age

​
Check Subscription Expiry

from datetime import date

subscription_end = date(2024, 12, 31)
today = date.today()
days_remaining = days_diff(today, subscription_end)

if days_remaining < 0:
    print("Subscription expired")
elif days_remaining < 7:
    print(f"Subscription expires in {days_remaining} days")
else:
    print("Subscription is active")

​
Business Day Calculations

from datetime import date, timedelta

def add_business_days(start_date, days):
  current = start_date
  added = 0
  
  while added < days:
    current = add_days(1, current)
    if is_weekday(current):
      added += 1
  
  return current

order_date = date(2024, 1, 15)  # Monday
delivery_date = add_business_days(order_date, 5)  # 5 business days later

​
Date Range Generation

from datetime import date

def date_range(start, end):
  dates = []
  current = start
  
  while current <= end:
    dates.append(current)
    current = add_days(1, current)
  
  return dates

start = date(2024, 1, 1)
end = date(2024, 1, 7)
week = date_range(start, end)
# [date(2024, 1, 1), date(2024, 1, 2), ..., date(2024, 1, 7)]

​
Report Date Filtering

from datetime import date

# Get dates for last 30 days
end_date = date.today()
start_date = days_ago(30)

# Filter records
records = get_all_records()
recent_records = [
    r for r in records 
    if start_date <= r['date'] <= end_date
]

​
Scheduled Task Checker

from datetime import date

def should_run_task(last_run_date, interval_days):
  next_run = add_days(interval_days, last_run_date)
  return date.today() >= next_run

last_backup = date(2024, 1, 1)
if should_run_task(last_backup, 7):
    print("Time to run weekly backup")

​
Weekend/Weekday Event Pricing

from datetime import date

def get_ticket_price(event_date):
  base_price = 50
  if is_weekend(event_date):
    return base_price * 1.5  # 50% weekend surcharge
  return base_price

event = date(2024, 2, 10)  # Saturday
price = get_ticket_price(event)  # 75.0

​
Next Steps

Lists

Learn about list operations

Dictionaries

Explore dictionary operations

Build docs developers (and LLMs) love

Get started for freeTalk to us