The fromisoformat() method of Python DateTime class

Overview:

The class method fromisoformat() creates a datetime object as per the string in ISO 8601 format.
With the ISO 8601 format several combinations of inputs are possible. Most frequently used ones are often the subset of the following full form: YYYY-MM-DDTHH:MM:YY±hh:mm. The trailing ±hh:mm specifies the UTC offset in hours and minutes.
There are also the less used ones like YYYY-WNN, Where W is the prefix and NN is the week number of the year.
When the day of a week is specified the format YYYY-WNN-D, W is the prefix and NN is the week number of the year and D is the day of the week.

Example 1:

# Example Python program that creates datetime
# objects from ISO 8601 format strings containing date
# and time information

from datetime import datetime

# Create the date for Christmas day
christmasDay = datetime.fromisoformat("2025-12-25")
print("Christmas day:")
print(christmasDay)

# Local time 3 PM on New year day
timeLocal = datetime.fromisoformat("2025-01-01 15:00")
print("Local time:")
print(timeLocal)

# Specify 2 PM EST on New year day
timeEST = datetime.fromisoformat("2025-01-01T14:00-05:00")
print("EST time:")
print(timeEST)

# Specify 11 AM UTC on New year day
timeUTC = datetime.fromisoformat("2025-01-01T11:00Z")
print("UTC:")
print(timeUTC)
print(type(timeUTC))

Output:

Christmas day:
2025-12-25 00:00:00
Local time:
2025-01-01 15:00:00
EST time:
2025-01-01 14:00:00-05:00
UTC:
2025-01-01 11:00:00+00:00
<class 'datetime.datetime'>

Example 2:

# Example Python program that creates a datetime
# object from an ISO 8601 format string containing week
# information

from datetime import datetime

# Create the first date of a given week
wk = datetime.fromisoformat("2025-W25")
print("First day of the 25th week:")
print(wk)

# Create the nth day of a given week
wk = datetime.fromisoformat("2025-W25-2")
print("Second day of the 25th week:")
print(wk)

Output:

First day of the 25th week:
2025-06-16 00:00:00
Second day of the 25th week:
2025-06-17 00:00:00