How do I remove the date format in LibreOffice Calc?

You can remove the date format in LibreOffice Calc in two primary ways: either by changing the format of cells that are already displaying a date, or by preventing Calc from automatically recognizing future input as a date.

Clearing Existing Date Formats from Cells

If your cells are currently showing dates (e.g., "01/01/2023") and you want them to display as plain numbers or text, you need to change their format. LibreOffice Calc stores dates as sequential numbers (serial numbers) starting from a specific base date. For instance, January 1, 1900, is typically stored as 1.

Applying 'Number' or 'Text' Format

This is the most common method to convert existing date-formatted cells back to a more general or specific non-date format.

Select the cells you wish to change.
Right-click on the selected cells and choose Format Cells... (or press Ctrl+1).
In the Format Cells dialog box, go to the Numbers tab.
Under the Category list, choose one of the following:
- Number: To display the underlying serial number of the date. You can also specify decimal places or separators.
- Text: To treat the cell content as literal text. If the cell originally contained a date, this might convert the displayed date into text (e.g., "01/01/2023" becomes the text string "01/01/2023", not its serial number). Be aware that if you apply "Text" format after a date has been entered and interpreted, it will keep the date's visual representation as text, not the serial number. For the serial number, use "Number".
- Standard: This is Calc's default format, which attempts to auto-recognize numbers, text, or dates. Choosing "Standard" might re-interpret the number as a date if it's within a valid date range, so use with caution if your goal is to explicitly remove date interpretation.
Click OK to apply the new format.

Practical Insight: If a cell displays "1/1/2023" and you format it as "Number," it will likely show "44927" (or a similar serial number, depending on Calc's date system settings). If you then want to convert this serial number back to text like "1/1/2023", you'd need to re-enter it as text or use a formula.

Clearing Direct Formatting

You can also try to clear direct formatting, which resets the cell's appearance to its default style.

Select the cells.
Go to Format > Clear Direct Formatting (or press Ctrl+M).

Note: This method might not always remove the date interpretation if the cell's underlying type was already determined as a date by Calc. It primarily clears explicit formatting like font, color, or number format if it was applied directly.

Preventing LibreOffice Calc from Automatically Recognizing Dates

LibreOffice Calc is designed to be smart and often converts input like "1-1" or "Jan 1" into a date format automatically. If you want to stop this behavior for future entries, especially for specific patterns, you have a few options.

Adjusting Date Acceptance Patterns (Global Setting)

This powerful feature allows you to control which input patterns Calc should not automatically interpret as dates. This is a global setting that affects how Calc handles new input.

Go to Tools > Options....
In the Options dialog, expand Language Settings and then select Languages.
Scroll down to find the Date acceptance patterns section.
Here, you will see a list of patterns (e.g., D/M/Y, D-M-Y, M/D/Y, M-D-Y, etc.) that Calc uses to recognize dates.
To prevent Calc from automatically recognizing a specific pattern as a date, remove the unwanted patterns from this list. For example, if you frequently type 1-1 intending it as a text string and Calc keeps turning it into a date, you might want to remove D-M or M-D patterns if they exist and are causing issues.
Click OK to save your changes.

Example: If you remove M-D-Y from the acceptance patterns, Calc will no longer automatically convert input like "01-01-2023" into a date. Instead, it might remain as text or be interpreted as a mathematical subtraction, depending on the format of the cell.

Pre-formatting Cells as Text for Specific Input

For specific columns or ranges where you know you'll be entering data that might look like a date but isn't (e.g., product codes like "10-2023"), you can pre-format the cells as 'Text'.

Select the cells or column where you want to enter non-date data.
Right-click on the selection and choose Format Cells....
Go to the Numbers tab.
Under Category, select Text.
Click OK.

Now, any input into these cells will be treated as text, regardless of whether it looks like a date.

Using an Apostrophe for Literal Text Input

For a one-off entry where you want to prevent automatic date conversion, simply precede your input with a single apostrophe (').

Example: Type '1-1 into a cell. Calc will display "1-1" as text and not convert it to a date. The apostrophe itself will not be visible in the cell after you press Enter.

Quick Reference Table: Date Formatting Control

Method	Purpose	How it Works	Impact
Format Cells > Numbers > Number/Text	Change existing date display to number/text.	Alters how the cell's content is visually represented without changing the underlying value (if it's a serial number).	Converts "01/01/2023" to "44927" (Number) or keeps "01/01/2023" as a text string (Text).
Format Cells > Numbers > Standard	Reset to default auto-recognition.	Attempts to automatically detect the data type.	May re-interpret numbers as dates if they fall within a valid date range. Not ideal for removing date format if auto-recognition is the problem.
Format > Clear Direct Formatting (Ctrl+M)	Remove explicitly applied formatting.	Resets visual styles to default.	May not change the underlying date interpretation if the cell was already recognized as a date.
Tools > Options > Language Settings > Languages > Date acceptance patterns	Prevent automatic date recognition for specific input patterns.	Globally modifies Calc's internal rules for interpreting input as dates.	Input matching removed patterns will no longer be auto-converted to dates, remaining as text or numbers.
Pre-format Cells as Text	Ensure all future input in selected cells is treated as text.	Sets the cell type to `Text` before data entry.	Any string entered (e.g., "1-1", "Mar 15") will be stored and displayed as literal text, not a date.
Use an Apostrophe (`'`)	Force text interpretation for a single entry.	The apostrophe tells Calc to treat the following characters as literal text.	" `'1-1` " will display as "1-1" without being converted to a date. The apostrophe is not visible.

By understanding and utilizing these methods, you can gain full control over how LibreOffice Calc handles date formats in your spreadsheets.