a period of time during which something can happen
▪ The shuttle's launch has a window of only two days. [=it can only happen within two specific days] ▪ The window of opportunity [=the time during which there is a chance to do something] has closed/ended.
I would say Do not take more than two pills within six hours.
Do not take more than 6 tablets within 24 hours or 10 tablets within 7 days.
Do not take more than 3 doses within 24 hours.
Student or Learner