Update date field from one module to the another

Update date field from one module to the another

Hi,

I have a module called "Cargo".
In this module there is a date field called "Fecha ETA".
Api name = Fecha_ETA


I have another module called "Deals".
In this module there is a date field called "ETA 2".
Api name = Fecha_Madrid


I need to create a function that when I update the ETA field in Cargo module, in Deals the field "ETA 2" is automatically updated with the same date as ETA + 1 Labor Day.

Thank you