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Excel's Volatile NOW Function for the Date and Time

Display the current date and time on a worksheet or calculate a value

By Ted French Ted French Writer Former Lifewire writer Ted French is a Microsoft Certified Professional who teaches and writes about spreadsheets and spreadsheet programs. lifewire's editorial guidelines Updated on March 5, 2020 Tweet Share Email Nongnuch Leelaphasuk / EyeEm / Getty Images Tweet Share Email MS Office Excel Word Powerpoint Outlook One of Microsoft Excel's best-known date functions is the NOW function. The NOW function adds the current date or time to a worksheet and can also calculate a value based on the current date and time, and have that value updated every time you open the worksheet. The information in this article applies to Excel versions 2019, 2016, 2013, 2010, and 2007, as well as Excel for Microsoft 365 for Mac, and Excel for Mac 2011. The NOW function syntax has no arguments. The data is entered inside the function's parentheses.

How to Enter the NOW Function

Like most Excel functions, the NOW function is entered into a worksheet using the function's dialog box. Because it takes no arguments, the function can be entered into the active cell by typing =Now() and pressing Enter. The result displays the current date and time. To change the information displayed, adjust the cell's formatting to show just the date or the time using the Format tab.

Shortcut Keys to Formatting Date and Time

Keyboard shortcuts help you quickly format the NOW function output. For the date (date-month-year format), enter Ctrl+Shift+#. For the time (hour-minute-second and a.m./p.m. format), enter Ctrl+Shift+@.

Serial Number or Date

The reason the NOW function takes no arguments is that the function obtains its data by reading the computer's system clock. Windows versions of Excel store the date as a number representing the number of full days since midnight January 1, 1900, plus the number of hours, minutes, and seconds for the current day. This number is called a serial number or serial date. Since the serial number continually increases with each passing second, entering the current date or time with the NOW function means the function's output continually changes.

Volatile Functions

The NOW function is a member of Excel's group of volatile functions, which recalculate or update every time the worksheet in which they're located recalculates, just as SUM and OFFSET do. For example, worksheets recalculate each time they're opened or when certain events occur, such as when you enter or change data, so the date or time changes unless automatic recalculation is turned off. To force the function to update at any time, press Shift+F9 to recalculate the active or current worksheet, or press F9 to recalculate all open workbooks. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire Use Excel's EOMONTH Function to Add or Subtract Months How to Combine the ROUND and SUM Functions in Excel Add the Current Date and Time in Google Sheets How to Use the DAY function in Excel How to Use the Google Spreadsheets AVERAGE Function How to Round Numbers Down in Excel With the ROUNDDOWN Function Use the Excel RIGHT Function to Extract Characters How to Use the Excel DATE Function How to Use the Round Function in Excel How to Use the Excel TRUNC Function How to Count Data in Selected Cells With Excel's COUNTIF Function Round up Numbers in Excel With the ROUNDUP Function Excel SUMIFS: Sum Only Values Meeting Multiple Criteria How to Use the MONTH Formula in Excel How to Use Excel's MROUND Function Excel SUM and OFFSET Formula Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies