Last month, I asked my son to help them "the next day/one day later/on Nov 27" - do I shift the time reference?

Question

In reported speeches, we have to change time references

How about an infinitive clause?

Let's assume right now is Dec 26 and last month, on Nov 11, I agreed to help on Nov 12.

Example 1

Me: Last month, I asked my son to help them the next day/one day later/on Nov 27.

Can I write Example 1 like that?

What if this is a case where I asked my son to help last month and the day he is going to help is tomorrow? Do I need to shift the time reference?

Example 2

(1)

Me: Last month, I asked my son to help them move tomorrow.

Or

(2) Me: Last month, I asked my son to help them move the next month.

Answer 1

You'd need to write example 1 this way - time expressions such as yesterday, tomorrow or ... days ago are always relative to the current time.

So no matter when you asked your son to help or how you structure your sentence, tomorrow will always refer to December 27th, and to refer to the day after you've asked your son to help you'd need to use one of the phrases in example 1.

That, of course, doesn't mean you can't use tomorrow in reported speech - just be careful as to which day it refers to.

It might be easier to understand if you realize that tomorrow can't be used for a day in the past outside of some very specific cases - you wouldn't say, assuming it's Wednesday:

On Monday, John bought a pair of shoes. *Tomorrow, he took them back to the store.