You can use the If you import data into Excel from another source, or if you enter dates with two-digit years into cells that were previously formatted as text, you may see a small green triangle in the upper-left corner of the cell.

You need to decrease by one since its the elapsed number of days, so if you only add the days, you'll get tomorrow instead of today.
The VALUE function will convert the text value to a numeric value. The VALUE function can also be used to convert dates and times to numbers. How?

No worry. Then copy the formula, select the cells that contain the text dates, and use Select a blank cell and verify that its number format is Click the cell that contains the text-formatted date that you want to convert.Press ENTER, and the DATEVALUE function returns the serial number of the date that is represented by the text date.Excel stores dates as sequential serial numbers so that they can be used in calculations. That lets you load an XLS or XLSX file with the number formatting preserved. For example, you may have entered a date in a cell that was formatted as text, or the data might have been imported or pasted from an external data source as text.Dates that are formatted as text are left-aligned in a cell (instead of right-aligned). Dates are stored as serial numbers in Excel and they can be switched from one format to another. To convert dates in place by adding zero, try Paste Special: Enter zero (0) in an unused cell and copy to the clipboard; Select the problematic dates The trick is that you have to provide the origin, which in Excel is December 30, 1899. as.Date(42705, origin = "1899-12-30") # [1] "2016-12-01" If you want to preserve your column types, you can try using the read_excel function from the readxl package. Follow these steps: Select a blank cell and verify that its number format is General.

Delete the figure you see and enter your original data again.

Select the number strings you want to convert to dates, and click Data > Text to Columns. As long as all these 8-digit numbers follow the YYYYMMDD pattern, there is a way to turn it back to Excel recognizable Date with a formula. After you drag the fill handle, you should have a range of cells with serial numbers that corresponds to the range of cells that contain text dates.Select the cell or range of cells that contains the serial numbers, and then on the Select the cell or range of cells that contains the text dates, and then on the To delete the serial numbers after all of the dates are converted successfully, select the cells that contain them, and then press DELETE.Convert text dates with two-digit years by using Error Checking Since dates are just numbers, this trick is a great way to convert dates in text format that Excel really should understand. See screenshot:In some times, you may directly enter dates as number string for saving time and enhancing working efficiency, but for formal cases, you need to convert these number strings to standard date formatting as below screenshot shown. To convert a date to a serial number, all you need to do is change the formatting to General: However, this won’t work if the date is stored as text. Although dates and times are stored as numbers in Excel and there is no need to convert them before using them in calculations, changing the data's format can make it easier to understand the result. Select the number string you want to convert to date and time, and pressIF there are multiple nonstandard dates needed to convert to standard date formatting, you can apply Select the dates or numbers strings you want to convert to standard dates, and clickThen you can see the selected dates have been converted to standard dates.
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