Pythonで日付の足し算、引き算をする

import datetime

now = datetime.datetime.now()
print(type(now)) # => <class 'datetime.datetime'>
print(now) # => 2022-02-08 21:46:45.976739

# 日付1日の増分
delta = datetime.timedelta(days=1)
print(type(delta)) # => <class 'datetime.timedelta'>
print(delta) # => 1 day, 0:00:00

tomorrow = now + delta
print(type(tomorrow)) # => <class 'datetime.datetime'>
print(tomorrow) # => 2022-02-09 21:46:45.976739

yesterday = now - delta
print(type(yesterday)) # => <class 'datetime.datetime'>
print(yesterday) # => 2022-02-07 21:46:45.976739

<class 'datetime.datetime'>
2022-02-08 21:46:45.976739
<class 'datetime.timedelta'>
1 day, 0:00:00
<class 'datetime.datetime'>
2022-02-09 21:46:45.976739
<class 'datetime.datetime'>
2022-02-07 21:46:45.976739