Date calculations - big thank you

[Dottor Zivago]

Hi Sean,
Thank you for your input. I have tried your suggestion and it works!!!

Sarah,
Your code works very well too!!!
I have downloaded your calendar stack and it is very nice and usefull.
Two questions for you:
- is it possible (without too much work) to have Monday as the first day of
week?
- I would like to show national holidays in different colours; is there an
easy way for a beginner to do this?

Thank you very much for your kind suggestions and sorry for my English.
Ciao from Italy
Ubaldo

PS "check that it is giving sensible answers before
telling people when their baby is due :-) "
As an obstetrician, the first thing you learn is that you can never trust
"LMP" of women; better dating pregnancy by ultrasound :-)