How do I basic calculations on a date range ?  Small vacation rental company

Discussion created by KorySkolnick on Oct 18, 2017
Latest reply on Oct 19, 2017 by KorySkolnick

The sales tax in my area increasing January 1, 2018 .  I want to to define a number or calc field based on check dates between certain date ranges but I don't want to change any of my previous data in that same field. I know I can "store" info but don't want to   Four instance , all reservations checking dates between January 1, 2018 and dec 31, 2018  should be 9.25% .  Checking dates between jan 1, 2019 and dec 31, 2019  should be 10.25% .   But I don't want to recalculate any of my previous records.  it's simple to do a search in the date fields for date ranges but  how do I do it in a calculation ?