Without User Exit --> Default current date for "Variable date"?

We can ahieve this with SAP Exit variable "Current Calendar day 0DAT". "Ready for input" flag is not checked for this variable. we need to give an option for end user to change the default current date. Looks like we can cahnge/check the flag "Ready for Input" for 0DAT variable.

are there any precautions we need to take after making changes to SAP exit variables?

Our main requirement is that we have 2 variables on Valid From & Valid To dates.

both the variables should default set to current date.

if end user changes 1 value, this value should be available to other variable as well. I've been told by end users that they are not comfortable with entering same value 2 times.

If we have only 1 variable, I can see that we can achieve this without user exit.

Looks like, I can't achieve this without user exit for 2 variables out of which one variable is derived from another variable.