5. Let the cell A1 contain the date and time such as 06-JAN-2021 10:43
In another cell the formula "=A1+1" is entered, (ignore the opening and closing inverted commas). Using the same format as cell A1, what will be shown in this cell?
From Quiz Excel-lent
Answer:
07-JAN-2021 10:43 (Incremented by one day)
To comprehend this, it is necessary to understand how Excel (and all other spreadsheets I have encountered) store dates. Dates are stored as an integer representing the number of days since an arbitrary start point. Usually, day 1 is the 1st January 1900 or 1st January 1904. Windows versions of Excel default to the former, those on Apple have traditionally used the latter. The principal advantage of the 1904 system is that a leap year occurs every four years for nearly two centuries whereas the former system in Excel fails to account for 1900 not being a leap year (apparently this is for compatibility with older spreadsheet programmes).
Time is stored as a fraction of the 24-hour day, eg 0.25 would represent 6am. Adding 1 to a date increases the integer part, the number of days since day 0. In the quoted example, the new date is the next day 07-JAN-2021. The numbers to the right of the decimal point are unchanged, thus the time element is unchanged.