Date and Time in Excel

How are date and time stored and formatted? In our previous section, we’ve already established that, no matter how date and/or time is formatted and possibly edited, underlying values saved in cells are still decimal numbers. Let’s expand on that. Excel era starts on January 1, 1900. If we enter number 1 in the cell and format it as date, the date we will see is in fact January 1, 1900. Zero will provide for a nonexistent date of January