present simple/future?

[hooshdar3]

Hi

The sentence is:

"She’s still in Taiwan. She doesn’t get back until next week."

Seems that does is used to refer to future!What is the rule?

[hooshdar3]

Another example:
"I get back on Friday afternoon. I’ll call you then."

[5jj]

“The present simple is frequently used for situations that often or regularly happen. It can therefore be used for a future situation that is part of a regular series of happenings:


The train for Berlin leaves at midnight tonight.

It is also used for something that is seen as part of a fixed timetable:


The sun rises at 07.34 tomorrow. (We can imagine the speaker thinking of a table of sunrise and sunset times.)


Emma sees Luke tomorrow. (We can imagine the speaker mentally looking at Emma’s diary).”

From: Ways of Expressing the Future in English

[hooshdar3]

“The present simple is frequently used for situations that often or regularly happen. It can therefore be used for a future situation that is part of a regular series of happenings:


The train for Berlin leaves at midnight tonight.

It is also used for something that is seen as part of a fixed timetable:


The sun rises at 07.34 tomorrow. (We can imagine the speaker thinking of a table of sunrise and sunset times.)


Emma sees Luke tomorrow. (We can imagine the speaker mentally looking at Emma’s diary).”

From: Ways of Expressing the Future in English

But examples I provided, don't indicate timetable events, as called by Micheal Swan.

[5jj]

They are fixed future events. Swan actually writes (my emphasis added): "This is common when we are talking about evenys which are part of a timetable, a regular schedule, or something similar".

Swan, Michael (1980) Practical English Usage (3rd ed, 2005.190), Oxford: OUP