Weird that no one helped you out on this....?
I think it really depends on how much of an overdose and what kind of calcium you are giving and how it was given.
I know that most chameleons get their daily powder supplements dusted on all of their food so the doses they would be getting would vary depending on how many dusted bugs they eat that day.
I would be more concerned about it if you are doing liquid calcium injections and you should probably call a vet in that case.` Otherwise, I would not be too concerned and just go back to your regular schedule. I don't think a little spike of calcium will hurt too much.
I'm no expert though, not even close! Hopefully someone with more experience will see this and give you some advice. But it would help if there was more info given about what kind of liquid calcium and what kind of dose you usually give and what kind of dose was given in this instance...
Good luck and I hope everything is okay.
