Time: Move "backwards" or "forwards"

Solution 1:

Summary

• If the date is relative to another date, you observe normal past/future relations.
• If the date is relative to a speaker, closer to the speaker is "forward" and further away is "backward"

I've certainly encountered this and I've noticed it's to do with the relative positioning of the dates compared to the speaker, not other dates.

I think I'll find this easier with an example and an illustration:

Given a person on a date, say the 1st September, place all of the relevant dates on imaginary pieces of card in straight lines in front and behind them representing future and past.

                            |>                   --->
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  :  :
 23 24 25 26 27 28 29 30 31 1  2  3  4  5  6  7  8  9
          AUG               ^          SEPT
                         Speaker

If they are "facing" the future, the Sep 9 card is behind the Sep 8 card, you are moving further away from the speaker, you are moving back.

 ------------>             <|
 :  |  |  |  :  |  |  |  |  |  |  |  |  |  |  |  |  |
 23 24 25 26 27 28 29 30 31 1  2  3  4  5  6  7  8  9
          AUG               ^          SEPT
                         Speaker

Similarly, this time the speaker is "facing" the past, they talk about moving an event from Aug 23 to Aug 27^*, they are moving it closer to themselves, ergo, forwards.

_{*It's a bit fruitless reorganising events in the past isn't it!}

Solution 2:

While there are a few cultures that think of the past as spatially in front of them, and the future behind them (their bodies), they are rare.

If the teacher was looking at or thinking of a calendar, moving an event "forward" would be like moving it closer to the front cover of the calendar, as though it were a book. From that perspective, "forward" is opposite from the relative norm. You would need to have a meta-communication about what time reference frames you're going to share, for clarity.