Calculate in-between-time - From https://arduino.stackexchange.com/questions/17477/creating-a-timer-using-a-real-time-clock-with-start-and-stop-times
if (
(
(nowHH > openHH) // check hours first
|| ( (nowHH == openHH) && (nowMM > openMM) ) // check minutes if in same hour
|| ( (nowHH == openHH) && (nowMM == openMM) && (nowSS >= openSS) ) // check seconds if in same hour & minute
)
&& // both conditions must be valid
(
(nowHH < closeHH) // check hours first
|| ( (nowHH == closeHH) && (nowMM < closeMM) ) // check minutes if in same hour
|| ( (nowHH == closeHH) && (nowMM == closeMM) && (nowSS <= closeSS) ) // check seconds if in same hour & minute
)
)