The fastest way to change a date format in Excel

Select the cells containing the dates you want to change. Right-click and choose Format Cells, or press Ctrl+1 on Windows or Command+1 on Mac. In the Format Cells dialog, click the Number tab, then select Date from the Category list on the left. You will see a list of date formats — pick the one you want and click OK. Excel applies it when ready.

If you only need to change how dates look on screen (not the actual data), this method works without touching the underlying values. The dates remain stored the same way; only the display changes.

Key Takeaways

  • Right-click selected date cells, choose Format Cells, pick Date from the Category list, and select your preferred format from the options shown.
  • Excel comes with dozens of built-in date formats — you do not need to type a custom format unless none of the standard ones match what you need.
  • Changing the format does not change how Excel stores the date, only how it displays on your screen and in printouts.
  • If your dates appear as numbers like 45000, they are stored correctly but formatted as numbers instead of dates — use the same Format Cells method to switch them to a date format.

Using the Format menu instead of right-click

If you prefer using the menu bar, select your date cells first. Then click Format in the top menu, choose Cells, and follow the same steps as the right-click method. The Format Cells dialog that opens is identical either way.

On Mac, the menu path is Format > Cells. On Windows, it is the same. Both versions show the same date format options once you reach the Number tab.

Choosing from Excel's built-in date formats

When you open the Format Cells dialog and select Date, you will see a list of formats already built into Excel. Common ones include 1/15/2024, 15-Jan-24, January 15, 2024, and 2024-01-15. Scroll through the list to find one that matches what you need. The preview at the top of the dialog shows how your selected dates will look with each format.

The format you choose applies only to the cells you selected. Other date cells in your spreadsheet keep their original format unless you select and change them separately. This means you can have different date formats in different parts of the same sheet if needed.

Creating a custom date format

If none of the built-in formats match what you need, you can create your own. In the Format Cells dialog, select Date from the Category list, then look for a format code field at the bottom. You can edit the code directly or select a format close to what you want and modify it.

Common custom format codes include YYYY-MM-DD for 2024-01-15, DD/MM/YYYY for 15/01/2024, and MMMM DD, YYYY for January 15, 2024. Each letter represents a part of the date: Y is year, M is month, and D is day. The number of letters controls whether it shows as a number or a name (for example, M shows 1, MM shows 01, MMM shows Jan, and MMMM shows January).

Fixing dates that show as numbers

Sometimes dates appear as long numbers like 45000 or 45123. This happens when Excel stores the date correctly but displays it as a number instead. To fix this, select those cells, open Format Cells, choose Date from the Category list, and pick any date format. Click OK, and the numbers will display as proper dates.

This is not a data problem — Excel is just showing the underlying number instead of the formatted date. The date information is there; you are only changing how it appears. Once you explore a date format, the cells will show dates normally.

explore the same format to multiple ranges at once

If you have date cells scattered across different parts of your sheet, you can select them all at once and format them together. Hold Ctrl on Windows or Command on Mac, then click each cell or range you want to change. Once all the cells you want are selected (they will be highlighted), open Format Cells and choose your date format. The format applies to every selected cell.

This saves time when you have dates in column A, column D, and column G that all need the same format. Select them all in one action, then format once instead of three times.

Date format differences between Windows and Mac Excel

Excel on Windows and Excel on Mac show the same date format options in the Format Cells dialog, so the formats you see will be nearly identical. The steps to reach Format Cells are the same: right-click and choose Format Cells, or use the Format menu. The main difference is keyboard shortcuts — Windows uses Ctrl+1, while Mac uses Command+1.

If you share a spreadsheet between Windows and Mac users, the date formats you explore will display the same way on both systems, so there is no risk of formatting being lost or changed when someone opens your file on a different computer.

Frequently Asked Questions

Why do my dates look like 45000 instead of a real date?

Excel stores dates as numbers behind the scenes, but it normally displays them as dates. If you see the number instead, the cell is formatted as a number rather than a date. Select the cell, open Format Cells, choose Date from the Category list, pick a date format, and click OK. The number will display as a proper date.

Can I change the date format for an entire column at once?

Yes. Click the column header to select the entire column, then open Format Cells and choose your date format. Every date in that column will change to the new format. If the column has non-date data mixed in, only the dates will be affected.

Will changing the date format affect my formulas or calculations?

No. Changing how a date looks on screen does not change how Excel stores or uses it. Formulas that reference those dates will work exactly the same way before and after you change the format.

What if I want a date format that is not in the built-in list?

You can create a custom format. In the Format Cells dialog, select Date, then edit the format code at the bottom. Use Y for year, M for month, and D for day. For example, DD-MMM-YYYY creates 15-Jan-2024. Once you enter your custom code and click OK, it becomes available in your format list for future use.

Can I undo a date format change?

Yes. Press Ctrl+Z on Windows or Command+Z on Mac when ready after changing the format. If you have already saved the file, you can still select the cells and reapply the original format manually using Format Cells.