On the Home tab, in the Number group, click the Dialog Box Launcher next to Number. You can also press CTRL+1 to open the Format Cells dialog box. In the Category list, click Date or Time. In the Type list, click the date or time format that you want to use.

To see a short date like 2/2/2013, select the cell, and then click Home > Number Format > Short Date. For a longer date like Saturday, February 02, 2013, pick Long Date instead. Tips for displaying dates

Fix text-formatted numbers by applying a number format. Format numbers as dates, currency, or even fractions to cells in a worksheet. For example, if you’re working on your quarterly budget, the Currency number format shows your numbers as money.

The DATEVALUE function converts a date that is stored as text to a serial number that Excel recognizes as a date. The DATEVALUE function is helpful in cases where a worksheet contains dates in a text format that you want to filter, sort, or format as dates, or use in date calculations.

Available number formats in Excel. In Excel, you can format numbers in cells for things like currency, percentages, decimals, dates, phone numbers, or social security numbers. Select a cell or a cell range. On the Home tab, select Number from the drop-down. Press CTRL + 1 and select Number.

You can use the built-in number formats in Excel as is, or you can create your own custom number formats to change the appearance of numbers, dates, and times.

To see a short date like 2/2/2013, select the cell, and then click Home > Number Format > Short Date. For a longer date like Saturday, February 02, 2013, pick Long Date instead. Tips for displaying dates

Use number formats to change the appearance of numbers, including dates and times, without changing the actual number. You can also change how negative numbers are displayed and control the display of digits after the decimal point in a number.

Excel supports two date systems, the 1900 date system and the 1904 date system. Each date system uses a unique starting date from which all other workbook dates are calculated. All newer versions of Excel calculate dates based on the 1900 date system, while older versions used the 1904 system.

You can add or subtract a number of days to or from a date by using a simple formula, or you can use worksheet functions that are designed to work specifically with dates in Excel.