That's a problem Pendulum is trying to solve

    d1 = datetime(2012, 1, 1, 1, 2, 3, tzinfo=pytz.UTC)
    d2 = datetime(2011, 12, 31, 22, 2, 3, tzinfo=pytz.UTC)
    delta = d2 - d1
    delta.days
    -1
    delta.seconds
    75600
    
    d1 = Pendulum(2012, 1, 1, 1, 2, 3)
    d2 = Pendulum(2011, 12, 31, 22, 2, 3)
    delta = d2 - d1
    delta.days
    0
    delta.hours
    -3