Date Picker

[kermitt]

Hello,

I have put inside my sheet a Date Picker where I can select a date from the date field named [date PERF].

What I would like to do is when I select a date via this date Picker in reality it selects this date + 15 days before.

Do you think it's possible via defining a function ?

Regards

[kermitt]

Erratum : 

Hello,

I have put inside my sheet a Date Picker where I can select a date from the date field named [date PERF].

What I would like to do is when I select a date via this date Picker in reality it selects this date - 15 days before.

Do you think it's possible via defining a function ?

Regards

[kermitt]

Does anybody have an idea ?