When I enter the formula =MONTH(TODAY()) and the cell formatting is set to
General, the cell contains a 1.
When I change the cell formatting to Custom "mmm", the cell displays "Jan".
So far, so good.
When I enter the formula =MONTH(TODAY())+3 and the cell formatting is set to
General, the cell contains a 4. I would assume that this is the correct
formula for showing the month which is 3 months hence. When I change the
formatting to Custom "mmm", I would expect the cell to contain "Apr", but it
doesn't. It still displays "Jan".
When I enter the formula =MONTH(TODAY()+45) and the cell formatting is set
to General, the cell contains a 3. I would assume that this is the correct
formula for showing the month which is 45 days hence. When I change the
formatting to Custom "mmm", I would expect the cell to contain "Mar", but it
doesn't. It still displays "Jan".

I'm stumped.

TIA,
David