It's not working

Hi. Am a beginner in programming and wanted to use local scheduled notifications. I used the code you provided but it doesn't seem to be working, both RTC and elapsed time. I wanted to use the scheduledRepeatingRTCNotification so that my app shows a notification everyday at 4pm. Is there anything I may have done incorrectly. Please guide me. And do I use 24hour clock? Is there somewhere I am supposed to call a certain method in the code you provided?