The NOW() is volatile. Every time we edit or re-open our spreadsheet, it recalculates and returns dynamic current date and time values. For example, consider the below table. Suppose we use the NOW() to enter the current date and time in cell A2. And then, using the keyboard shortcut, Ctrl + ;, " ", and then Ctrl + Shift + ;, we update the required value in cell A3. Now, assume we save and close the worksheet and re-open it after a minute. Then, we will see the refreshed current date and time in cell A2, containing the NOW(), as depicted in the below image.