# Date & Time Functions

These spreadsheet functions are used for inserting and editing dates and times.

**Insert - Function** - Category **Date&Time**

LibreOffice internally handles a date/time value as a numerical value. If you assign the numbering format "Number" to a date or time value, it is converted to a number. For example, 01/01/2000 12:00 PM, converts to 36526.5. The value preceding the decimal point corresponds to the date; the value following the decimal point corresponds to the time. If you do not want to see this type of numerical date or time representation, change the number format (date or time) accordingly. To do this, select the cell containing the date or time value, call its context menu and select **Format Cells**. The **Numbers** tab page contains the functions for defining the number format.

## Date base for day zero

Dates are calculated as offsets from a starting day zero. You can set the day zero to be one of the following:

Date base | Use |
---|---|

'12/30/1899' | (default) |

'01/01/1900' | (used in former StarCalc 1.0) |

'01/01/1904' | (used in Apple software) |

Choose **Tools - Options'** *- LibreOffice Calc - Calculate'* to select the date base.

## Two digits years

In **Tools - Options'** *- LibreOffice - General'* you find the area **Year (two digits)**. This sets the period for which two-digit information applies. Note that changes made here have an effect on some of the following functions.