Change auctions house duration

Hello,

i searched for a while to change the Values for the auction Duration Dropdown Field.
I am trying to change the following values:
https://imgur.com/a/aNS4lIR

In the Interface.fdb i found a lua file for this function i found the auctionframe.lua. But i dont see where the Variables are set.
https://imgur.com/a/8ANucAD

Am I completely on the wrong track?
Do you have a tips for me?

thank you in advance!