Instruction note says when setting current time during DST period & DST function is ON your current time should be the time after DST" Explain?

Daylight saving time starts and ends at specific times. For example in 2018 DST begins (aka "during DST period") March 11th and ends November 4th. So if you are setting your timer anytime between these dates you want to set it a hour behind because after DST (Ends Nov 4th){fall behind})your time would be set a hour behind. Hope this helps

If it's during daylight savings time, you would need to set the clock 1 hour behind what it currently is in your area(I.E. if its 4pm for you, you would set the timer to 3pm). If you set it to your current time, it will actually set you an hour ahead due to the DST.