IMO i would wait until you are at home with him, just so you can keep an eye on him. There is always a slight chance that he could be sick, and of course if you aren't there you won't notice, which also means he wouldn't have absorbed the wormer.
I usually give mine when i know i am around for the whole day, especially since one of my girls was sick with a wormer.
i waited a couple of days and then re-administered.
she was fine the next time though.