How to check if midnight has just passed?

Question

I need a function returning a boolean indicating if midnight has just passed. I came up with this but I am not happy with the "form". Can anyone think of anything better? as in terms of efficiency/elegance?

from datetime import datetime, timedelta
   
def passed_midnight(delta=1):
    time_now = datetime.today   # see other comment below
    time_ago = time_now() - timedelta(minutes=delta)
    # next line with a dummy delta (zero) cuz "datetime.today - timedelta(days=1)" gives an error
    today = time_now() - timedelta(days=0)
    return today.strftime("%Y%m%d") != time_ago.strftime("%Y%m%d")

>>> print(passed_midnight, 10)

Answer 1

• datetime.today - timedelta(days=1) gives an error because datetime.today is a function that needs to be called. This is why you must have felt the need to write time_now() with parentheses: it's calling the function, twice (with different results, because time has a tendency to pass).
• Avoid strftime in favour of date(), which returns the date part only (as a datetime.date object).
• Use datetime.now() instead of datetime.today() so that subtracting a timedelta can take the timezone (and hence daylight savings time changeovers) into account.

So then you get this:

from datetime import datetime, timedelta
   
def passed_midnight(delta=1):
    time_now = datetime.now()
    time_ago = time_now - timedelta(minutes=delta)
    return time_now.date() != time_ago.date()

Answer 2

You probably misunderstood how to declare a function and how to call it. Here is a version that fixed the issues with function calls:

from datetime import datetime, timedelta

def passed_midnight(delta=1):
    today = datetime.today()
    time_ago = today - timedelta(minutes=delta)
    return today.strftime("%Y%m%d") != time_ago.strftime("%Y%m%d")

>>> print(passed_midnight(10))
False

Be careful, this code doesn't take care of time zones. The behavior will be different from a location to another