20 iOS Secret Features You Likely Didn’t Know About13. Change the alert systemImage Credit: https://www.pinterest.com/pin/127086020711728757/Go to Settings then Mail, Contacts & Calendar >then Default Alert Times (which is close to the bottom) and adjust your times accordingly.Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20