Working with dates and times is a common requirement in many Python applications — from logging and timestamps to time-based data processing and automation. Python’s built-in datetime module provides a powerful and flexible set of tools for handling these tasks.
In this tutorial, you’ll learn:
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What the
datetimemodule is -
How to work with dates and times
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Formatting and parsing date strings
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Performing date arithmetic
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Real-world use cases
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Tips and common pitfalls
What is the datetime Module?
Python’s datetime module supplies classes for manipulating dates and times in both simple and complex ways. It supports:
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Date and time arithmetic
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Time zones
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Formatting and parsing
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And more
To use it, you simply:
import datetime
Core Classes in datetime
| Class | Description |
|---|---|
date |
Handles dates (year, month, day) |
time |
Handles time (hour, minute, second, microsecond) |
datetime |
Combines both date and time |
timedelta |
Represents the difference between two dates/times |
timezone |
Supports time zone info |
Working with Dates
Create a date object:
from datetime import date
today = date.today()
print("Today's date:", today)
Access date components:
print(today.year)
print(today.month)
print(today.day)
Create a specific date:
d = date(2025, 12, 25)
print("Christmas:", d)
⏰ Working with Time
from datetime import time
t = time(14, 30, 45)
print("Time:", t) # Output: 14:30:45
print("Hour:", t.hour)
Working with Date and Time
from datetime import datetime
now = datetime.now()
print("Current datetime:", now)
specific = datetime(2025, 5, 7, 14, 0)
print("Specific datetime:", specific)
Replace components:
new_time = now.replace(hour=9, minute=0)
print("Modified time:", new_time)
Date Arithmetic with timedelta
from datetime import timedelta
delta = timedelta(days=7)
print("7 days:", delta)
future = datetime.now() + delta
print("One week from now:", future)
past = datetime.now() - timedelta(days=30)
print("30 days ago:", past)
Formatting Dates (strftime)
Convert a datetime object to a string:
now = datetime.now()
print(now.strftime("%Y-%m-%d %H:%M:%S"))
Common format codes:
| Code | Meaning | Example |
|---|---|---|
%Y |
Year (4 digits) | 2025 |
%m |
Month (01–12) | 05 |
%d |
Day (01–31) | 07 |
%H |
Hour (00–23) | 14 |
%M |
Minute | 30 |
%S |
Second | 45 |
Parsing Dates (strptime)
Convert a string into a datetime object:
dt = datetime.strptime("2025-05-07 14:00:00", "%Y-%m-%d %H:%M:%S")
print("Parsed datetime:", dt)
Working with Time Zones
from datetime import datetime, timezone, timedelta
utc_time = datetime.now(timezone.utc)
print("UTC Time:", utc_time)
# Create a time zone offset of +5:30 (e.g., IST)
ist = timezone(timedelta(hours=5, minutes=30))
local_time = utc_time.astimezone(ist)
print("IST Time:", local_time)
✅ Complete Example
from datetime import datetime, timedelta
# Get current date and time
now = datetime.now()
print("Now:", now)
# Add 10 days
future_date = now + timedelta(days=10)
print("10 days from now:", future_date)
# Format date
formatted = now.strftime("%A, %d %B %Y %I:%M %p")
print("Formatted:", formatted)
# Parse a date string
parsed = datetime.strptime("2025-12-31 23:59:59", "%Y-%m-%d %H:%M:%S")
print("Parsed:", parsed)
# Difference in days
days_left = parsed - now
print("Days until new year:", days_left.days)
Tips for Using datetime
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✅ Use
datetime.now()for local time,datetime.utcnow()for UTC -
✅ Use
timedeltafor date arithmetic instead of manually adjusting components -
✅ Use
strftime()for readable output and logging -
✅ Use
strptime()for parsing date strings into objects -
✅ Leverage time zones with
timezoneif you work with multiple regions
⚠️ Common Pitfalls
| Pitfall | Solution |
|---|---|
| ❌ Mixing naive and aware datetime objects | Always convert to same time zone before comparing |
❌ Using wrong format in strptime() |
Make sure the string matches the format string exactly |
| ❌ Forgetting to import specific classes | Use from datetime import datetime, timedelta for clarity |
❌ Assuming datetime.now() is UTC |
Use datetime.utcnow() or datetime.now(timezone.utc) |
Summary Table
| Task | Method |
|---|---|
| Get current date/time | datetime.now() |
| Create custom date/time | datetime(2025, 5, 7, 14, 0) |
| Format datetime | .strftime("%Y-%m-%d") |
| Parse datetime | datetime.strptime("2025-05-07", "%Y-%m-%d") |
| Add/Subtract time | datetime +/- timedelta(days=...) |
| Time zones | datetime.now(timezone.utc) |
Final Thoughts
The datetime module is a powerful tool for handling all your date and time needs in Python — whether it's scheduling, timestamping, logging, or working across time zones.
By mastering the datetime module, you’ll gain better control over time-based data in your applications and write cleaner, more accurate programs.
Tips and Tricks
What is pass in Python?
Python | Pass Statement
The pass statement is used as a placeholder for future code. It represents a null operation in Python. It is generally used for the purpose of filling up empty blocks of code which may execute during runtime but has yet to be written.
def myfunction():
pass
How can you generate random numbers?
Python | Generate random numbers
Python provides a module called random using which we can generate random numbers. e.g: print(random.random())
We have to import a random module and call the random() method as shown below:
import random
print(random.random())
The random() method generates float values lying between 0 and 1 randomly.
To generate customized random numbers between specified ranges, we can use the randrange() method
Syntax: randrange(beginning, end, step)
import random
print(random.randrange(5,100,2))
What is lambda in Python?
Python | Lambda function
A lambda function is a small anonymous function. This function can have any number of parameters but, can have just one statement.
Syntex:
lambda arguments : expression
a = lambda x,y : x+y
print(a(5, 6))
It also provides a nice way to write closures. With that power, you can do things like this.
def adder(x):
return lambda y: x + y
add5 = adder(5)
add5(1) #6
As you can see from the snippet of Python, the function adder takes in an argument x and returns an anonymous function, or lambda, that takes another argument y. That anonymous function allows you to create functions from functions. This is a simple example, but it should convey the power lambdas and closures have.
What is swapcase() function in the Python?
Python | swapcase() Function
It is a string's function that converts all uppercase characters into lowercase and vice versa. It automatically ignores all the non-alphabetic characters.
string = "IT IS IN LOWERCASE."
print(string.swapcase())
How to remove whitespaces from a string in Python?
Python | strip() Function | Remove whitespaces from a string
To remove the whitespaces and trailing spaces from the string, Python provides a strip([str]) built-in function. This function returns a copy of the string after removing whitespaces if present. Otherwise returns the original string.
string = " Python "
print(string.strip())
What is the usage of enumerate() function in Python?
Python | enumerate() Function
The enumerate() function is used to iterate through the sequence and retrieve the index position and its corresponding value at the same time.
lst = ["A","B","C"]
print (list(enumerate(lst)))
#[(0, 'A'), (1, 'B'), (2, 'C')]
Can you explain the filter(), map(), and reduce() functions?
Python | filter(), map(), and reduce() Functions
- filter() function accepts two arguments, a function and an iterable, where each element of the iterable is filtered through the function to test if the item is accepted or not.
>>> set(filter(lambda x:x>4, range(7))) # {5, 6}
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map() function calls the specified function for each item of an iterable and returns a list of result
>>> set(map(lambda x:x**3, range(7))) # {0, 1, 64, 8, 216, 27, 125}
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reduce() function reduces a sequence pair-wise, repeatedly until we arrive at a single value..
>>> reduce(lambda x,y:y-x, [1,2,3,4,5]) # 3Let’s understand this:
2-1=1
3-1=2
4-2=2
5-2=3Hence, 3.
What is a namedtuple?
Python | namedtuple
A namedtuple will let us access a tuple’s elements using a name/label. We use the function namedtuple() for this, and import it from collections.
>>> from collections import namedtuple
#format
>>> result=namedtuple('result','Physics Chemistry Maths')
#declaring the tuple
>>> Chris=result(Physics=86,Chemistry=92,Maths=80)
>>> Chris.Chemistry
# 92
Write a code to add the values of same keys in two different dictionaries and return a new dictionary.
We can use the Counter method from the collections module
from collections import Counter
dict1 = {'a': 5, 'b': 3, 'c': 2}
dict2 = {'a': 2, 'b': 4, 'c': 3}
new_dict = Counter(dict1) + Counter(dict2)
print(new_dict)
# Print: Counter({'a': 7, 'b': 7, 'c': 5})
Python In-place swapping of two numbers
Python | In-place swapping of two numbers
>>> a, b = 10, 20
>>> print(a, b)
10 20
>>> a, b = b, a
>>> print(a, b)
20 10
Reversing a String in Python
Python | Reversing a String
>>> x = 'PythonWorld'
>>> print(x[: : -1])
dlroWnohtyP
Python join all items of a list to convert into a single string
Python | Join all items of a list to convert into a single string
>>> x = ["Python", "Online", "Training"]
>>> print(" ".join(x))
Python Online Training
python return multiple values from functions
Python | Return multiple values from functions
>>> def A():
return 2, 3, 4
>>> a, b, c = A()
>>> print(a, b, c)
2 3 4
Python Print String N times
Python | Print String N times
>>> s = 'Python'
>>> n = 5
>>> print(s * n)
PythonPythonPythonPythonPython
Python check the memory usage of an object
Python | Check the memory usage of an object
>>> import sys
>>> x = 100
>>> print(sys.getsizeof(x))
28
