Used OS version: Big sur 11.2 Here is the log: 2021-02-05 12:06:31.717666+0200 test2[50111:1553156] * Assertion failure in -[UIDatePickerCalendarDaySet daysForMonth:includingOverlapDays:], UIDatePickerCalendarDaySet.m:132 2021-02-05 12:06:31.768670+0200 test2[50111:1553156] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid calculation: number of calculated days is not dividable by the number of days in a week.' First throw call stack: ( 0   CoreFoundation                      0x00007fff20421af6 _exceptionPreprocess + 242 1   libobjc.A.dylib                     0x00007fff20177e78 objcexceptionthrow + 48 2   CoreFoundation                      0x00007fff2042191f +[NSException raise:format:] + 0 3   Foundation                          0x00007fff2077156a -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191 4   UIKitCore                           0x00007fff24bff44b -[UIDatePickerCalendarDaySet daysForMonth:includingOverlapDays:] + 1338 5   UIKitCore                           0x00007fff241b37e3 -[UIDatePickerCalendarViewDataSourceController prepareDataSourceWithScrollPositionIfNecessary:] + 493 6   UIKitCore                           0x00007fff242a2223 112-[UIDatePickerCalendarDateView setVisibleMonth:animated:updateDataSource:updateCollectionView:notifyDelegate:]blockinvoke + 60 7   UIKitCore                           0x00007fff242a2275 -[UIDatePickerCalendarDateView performIgnoringScrollCallbacks:] + 59 8   UIKitCore                           0x00007fff242a2184 -[UIDatePickerCalendarDateView setVisibleMonth:animated:updateDataSource:updateCollectionView:notifyDelegate:] + 192 9   UIKitCore                           0x00007fff242a1afb -[UIDatePickerCalendarDateView setSelectedDate:animated:updateVisibleMonth:updateCollectionView:notifyDelegate:] + 282 10  UIKitCore                           0x00007fff242a19db -[UIDatePickerCalendarDateView setSelectedDate:animated:] + 40 11  UIKitCore                           0x00007fff23b4b8a3 -[UIDatePickerCalendarView updateSelectedDay:time:animated:notify:] + 936 12  UIKitCore                           0x00007fff23b4b9d8 -[UIDatePickerCalendarView updateSelectedDay:animated:notify:] + 106 13  UIKitCore                           0x00007fff23b4bbe2 -[UIDatePickerCalendarView updateSelectedDayToDayInMonth:animated:notify:] + 351 14  UIKitCore                           0x00007fff23b4c00e -[UIDatePickerCalendarView monthYearSelector:didSelectMonth:] + 60 15  UIKitCore                           0x00007fff24ad2c60 -[UIDatePickerCalendarMonthYearSelector setSelectedMonth:animated:updatePicker:notifyDelegate:] + 236 16  UIKitCore                           0x00007fff24ad2d91 -[UIDatePickerCalendarMonthYearSelector didSelectDate:] + 172 17  UIKitCore                           0x00007fff2469d19e -[UIApplication sendAction:to:from:forEvent:] + 83 18  UIKitCore                           0x00007fff23fc6684 -[UIControl sendAction:to:forEvent:] + 223 19  UIKitCore                           0x00007fff23fc69a7 -[UIControl sendActionsForEvents:withEvent:] + 332 20  UIKitCore                           0x00007fff24615bf9 -[UIDatePickerView pickerView:didSelectRow:inComponent:] + 395 21  UIKitCore                           0x00007fff24621f65 -[UIPickerView sendSelectionChangedForComponent:notify:] + 103 22  UIKitCore                           0x00007fff2461c2bd -[UIPickerTableView scrollingFinished] + 184 23  UIKitCore                           0x00007fff2461c4c0 -[UIPickerTableView scrollViewDidEndDecelerating:] + 27 24  UIKitCore                           0x00007fff24b8628a -[UIScrollView scrollViewDidEndDeceleratingForDelegate] + 148 25  UIKitCore                           0x00007fff24b7ffc1 -[UIScrollView stopScrollDecelerationNotify:] + 560 26  UIKitCore                           0x00007fff24b80227 -[UIScrollView stopScrollingNotify:pin:tramplingDragFlags:] + 508 27  UIKitCore                           0x00007fff248bfe42 -[UITableView stopScrollingNotify:pin:] + 42 28  UIKitCore                           0x00007fff24b75526 -[UIScrollView smoothScrollWithUpdateTime:] + 3278 29  UIKitCore                           0x00007fff24b75794 -[UIScrollView smoothScrollDisplayLink:] + 395 30  QuartzCore                          0x00007fff279c32b9 ZN2CA7Display11DisplayLink14dispatchitemsEyyy + 755 31  QuartzCore                          0x00007fff27aa8dbc ZL22displaytimercallbackP12_CFMachPortPvlS1 + 639 32  CoreFoundation                      0x00007fff2035d9d8 _CFMachPortPerform + 157 33  CoreFoundation                      0x00007fff20390c82 CFRUNLOOPISCALLINGOUTTOASOURCE1PERFORMFUNCTION + 41 34  CoreFoundation                      0x00007fff20390023 CFRunLoopDoSource1 + 614 35  CoreFoundation                      0x00007fff2038a4f2 CFRunLoopRun + 2353 36  CoreFoundation                      0x00007fff203896d6 CFRunLoopRunSpecific + 567 37  GraphicsServices                    0x00007fff2c257db3 GSEventRunModal + 139 38  UIKitCore                           0x00007fff24696cf7 -[UIApplication run] + 912 39  UIKitCore                           0x00007fff2469bba8 UIApplicationMain + 101 40  libswiftUIKit.dylib                 0x00007fff551885f2 $s5UIKit17UIApplicationMainys5Int32VAD_SpySpys4Int8VGGSgSSSgAJtF + 98 41  test2                               0x00000001093ccaea $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ + 122 42  test2                               0x00000001093cca5e $s5test211AppDelegateC5$mainyyFZ + 46 43  test2                               0x00000001093ccb39 main + 41 44  libdyld.dylib                       0x00007fff2025a3e9 start + 1 45  ???                                 0x0000000000000001 0x0 + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid calculation: number of calculated days is not dividable by the number of days in a week.' terminating with uncaught exception of type NSException CoreSimulator 732.18.6 - Device: iPhone 12 Pro (52D9022C-204E-4C1E-9596-1BFA46B08979) - Runtime: iOS 14.4 (18D46) - DeviceType: iPhone 12 Pro (lldb) 

I was able to get a real device to test. Seems to be working fine on it. Maybe as pointed out by Claude31 it's either Xcode installation issue or something with the OS of the simulators. Thanks for everyone's time.

Hi, Thanks for the attempt, I had created a video, maybe I am missing something? Here is the video: youtu.be/hjskPTB0Ok8 I am using: Version 12.4 (12D4e)

Sometimes the most basic answer is the most correct. Creating IBAction will do it. Please close the ticket as I cannot find "Edit/Delete" post option.