How are date and time stored and formatted? No matter how date and/or time are formatted and possibly edited, the underlying values saved in cells are still decimal numbers. Given that Excel’s era starts on January 1, 1900, if we enter number 1 in the cell and format it as a date, the date we will see is in fact January 1, 1900.Zero will provide for a nonexistent date of January 0, 1900, and a negative number will result in …
