Why this result always in a kind of: TypeError: unsupported opperand type (s) for - : 'datetime.delta' and 'int'

Question

Code:
from datetime import date
print "Starting.."
release = date (2017, 8,21)
now = date.today ()
until = release - now
nights = until - 1
print " [*] Days until release: %s" % (until)
print " [*] Nights until release: %s" % (nights)
>>> nights = until - 1 (rest see above)

i did release - now.
this returns no TypeError because both are datetime/date objects?

Plztell me, if this is the right Error- cause
if no:
give me please a note/start-up what it could be
if yes:
same like yes but note how to solve it.

Answer 1

Yes, the release-now works because they are both dates, until-1 doesn't work because it doesn't know how to subtract an int from a date (which makes sense because it could mean 1 day, 1 week, 1 month...) use timedelta.

from datetime import timedelta
until-timedelta​(days=1)

Answer 2

Thank you. I learned much about timedelta, time and date.

If anyone got a similar problem, people can take a look how i solved it, in "intro".