Quick question on FRA casting

[Douglas Muir 406]

If you cast a spell that is a FRA, does it take effect (1) at the end of the round, (2) at the very beginning of the next round, or (3) on your initiative in the next round?

many thanks,

Doug M.

[Are]

If the casting time is 1 full-round action, then it comes into effect as that action ends on your turn (which may be the end of your turn, depending on if you're taking a swift action, a 5-ft-step, or similar afterwards).

Note: That casting time is usually reserved for spontaneous casters applying metamagic to their spells. Regular spells rarely, if ever, have 1 full-round action as their casting time.

If the casting time is 1 round, then the spell comes into effect just before your initiative count on the following round.