Is there any word for describing something that is about time ?
For example," ... you can not do that either for financial reasons or [something about time] reasons"
Sometimes people refer to "scheduling reasons" (difficulty in fitting something into a schedule) or "logistical reasons" (planning reasons). "Time reasons" is occasionally used but is a fairly uncommon usage and doesn't sound particularly natural here.
I would say:
You cannot do so for reasons of either time or money
You cannot do so either for financial reasons or due to time constraints
You cannot do so due to constraints of either time or money
Yes, there is a word meaning "of or relating to time"; it's "temporal".