The receipt with the wrong date

A shop receipt says 05/12/2026. Is that 5 December or 12 May? In the UK it is 5 December. In the USA it is 12 May.

Programs need to read dates and show dates. Python has pre-written code for this. This lesson shows three commands.

Key words

Word	What it means	Example
datetime	A Python library (a set of ready-made code) for dates and times.	from datetime import datetime
now()	Gives the date and time right now.	datetime.now()
Format code	A short code, such as %d, that stands for one part of a date.	%Y is the year
strftime()	Turns a date into text. The name means "string from time".	when.strftime("%d/%m/%Y")
strptime()	Turns text into a date. The name means "string parse time".	datetime.strptime("25/12/2026", "%d/%m/%Y")
String	Text inside quote marks.	"25/12/2026"
Function	A named piece of code that does one job.	len()
Validation	Checking that data is correct and makes sense before you use it.	Is this a real date?

The cells students fill in are left blank in this preview.

Try it: the date right now

Code: python

from datetime import datetime

now = datetime.now()
print(now)
print(now.strftime("%d/%m/%Y"))
print(now.strftime("%H:%M"))

# Run it twice. The answer changes, because the time moves on.

A date is not the same as text

Inside Python, a date is a special kind of value. It is not the same as the letters and digits you see on a screen.

Text is only letters and digits. To show a date to a person, you make text from it. To use text that a person typed, you make a date from it.

Two commands do these jobs. They go in opposite directions.

Worked example: the format codes

Code	Stands for	Example for 25 December 2026, 9:30 am
%d	Day of the month, two digits	25
%m	Month as a number, two digits	12
%Y	Year, four digits	2026
%B	Month name in full	December
%A	Day of the week in full	Friday
%H	Hour on a 24 hour clock	09
%M	Minutes	30

The cells students fill in are left blank in this preview.

Try it: date to text

Code: python

from datetime import datetime

when = datetime(2026, 12, 25, 9, 30)

print(when.strftime("%d/%m/%Y"))
print(when.strftime("%A %d %B %Y"))
print(when.strftime("%H:%M"))

# Change the format text. Try "%Y-%m-%d".
# Anything that is not a code, such as the / sign, is copied as it is.