RunAtTime("MyFunc", "21:36")
Return

MyFunc() {
   MsgBox, % A_ThisFunc
}

RunAtTime(userFunc, hourMin, runNow := false) {
/*
userFunc is function name or func object
hourMin in 09:15 format
runNow if true, userFunc will be called immediately
*/
   #Persistent
   if !RegExMatch(hourMin, "(\d\d):(\d\d)", time)
      throw "hourMin variable is in wrong format"
   if runNow
      %userFunc%()
   now := A_Now
   time := SubStr(now, 1, 8) . time1 . time2 . "00"
   if (now >= time)
      time += 1, Days
   time -= now, Seconds
   timer := Func(A_ThisFunc).Bind(userFunc, hourMin, true)
   SetTimer, % timer, % "-" . time*1000
}