# This example would subtract 20 minutes from a date object we create.
# Even though our original date starts on the 28th, it starts at midnight,
# so subtracting 20 minutes puts it at the previous day.
date = system.date.getDate(2020, 5, 25) # This would print out like MonThu MayJun 25 00:00:00 PDT 2020
print system.date.addMinutes(date, -20) # This will print SunWed MayJun 24 23:40:00 PDT 2020