Please explain to me the meaning of the phrase:
Two weeks ago tomorrow.
It seems to be in the past (ago) but with a link to the future (tomorrow).
It's the same as saying:
So whatever he is talking about happened 13 days ago.
It means that as of tomorrow, it will have been two weeks from the date in question. In other words, it means two weeks ago minus one day (the difference between today and tomorrow).
This is part of a far wider form of contraction of future date indirect references, or past references from future dates.
Is as said above, two weeks ago, from tomorrow. Removing ago, gives a future, and more common, rendering.
That is two weeks from tomorrow.
This is most commonly used with days of the week.
A week from the next Tuesday. Confusingly, this is also used identically to mean the previous Tuesday if going backwards, so one week before the previous Tuesday. Forward is much more common, and if it is backwards, knowledge of that will either be via context, or use of ago within it.
So you can have conversations along the following lines:
"N weeks ago tomorrow" refers to a time that is << N * 7 >> days prior to tomorrow (and necessarily, << (N * 7) - 1 >> days prior to the day on which the phrase was uttered or written).
In reply to "Orbling" and "Peter Shor" (because I do not yet authority to leave comments on this StackExchange site):
In spoken American English, "Sunday week" and "Friday week" as demonstrated by Orbling may be expressed as "Sunday a week" and "Friday a week".
The past-indicating version can be interpreted as"Sunday a week ago", and the future-indicating version as either "Sunday a week from now" or "Sunday in a week".