Even now, Apple still has not fixed a leap year bug in the Calendar app for iOS.
Confusingly, while the calendars for 2100, 2200, 2300, 2500, 2600, etc. correctly omit February 29, the calendars for 1700, 1800, and 1900 incorrectly show both "February 29" and "March 1" under the Monday, Saturday, and Thursday columns respectively. All the other dates in those three years are shown under the correct column.
Please make the calendar omit February 29 for 1700, 1800, 1900, and earlier proleptic Gregorian centuries.