Light timer failed. Help please

My lights in my flower room were supposed to go off but the timer failed and they stayed on for 21 hours instead of 12. The plants are at different stages of flower.
Some are 2 weeks in and some are 8 weeks into flower. What should I do?
Thanks

Just put them back on their original schedule, that's all you can do.

Theoretically you gave them a tiny bit of a stress, but realistically you did very little if anything to set them back.

Don't worry about it.