TOF Style timer with tags (no PLC)

I have two tags, I want tag A and B (bools) to go high at the same time, but I want tag B to go off 30 minutes after tag A does. What is the best way to accomplish in Ignition, no PLC involved in this application.

What ever event occurs to turn off A and B, have it write a timestamp to a tag. Then you can compare now to that time plus what ever offset you want and keep B true until then.

The same would work for a TON configuration, you would just keep B off until the set time elapsed.

I would use Louis' approach, but have the event on tag A add the time interval to now() before writing to the timestamp tag, so that timestamp tag has the cut off time. The expression tag for B would then have:

{[.]A} || dateIsAfter({[.]CutoffTS}, now())

Adjust the now() fragment for how precise you want the cutoff.