Student or Learner
-I am staying here for a month in total.
-I will be staying here for 2 days.
-I am going there for 2 hours.
-I am staying here all night long.
We can say that the month(day) has started already, although there's no indication of when. For this reason we can use 'for' with this ways in present continuous or future continuous?
In the third sentence, we have no idea when the two-hour period will start. The speaker has not yet arrived 'there'.
We can use 'for' + a time period with any tense to inducate the duration of a situation:
I stayed/was staying/have been staying/am staying/will stay/ will be staying at my mother's for a month.