Delay your turn

That's not part of the 5e rules. The 5e devs didn't want it as a rule.

There is no delay action. Just ready. Of course Ready can be a lot more specific in the tabletop game than it is in Solasta, but in the SRD and 5E, delay isn't a thing.

Yeah, a lot of durations and effects in 5E are tied to the start or end of a creatures turn. Being able to delay would open those things up for abuse, which is why it's not an option in 5E.