If you want to highlight dates that occur in the next N days with conditional formatting, you can do so with a formula that uses the TODAY function with AND. This is a great way to visually flag things like expiration...

Note: Excel has several built-in data validation rules for dates. This page explains how to create a your own validation rule based on a custom formula in case you want or need more control and flexibility.
To allow a...

To calculate the number of days before a certain date, you can use subtraction and the TODAY function. In the example, D5 contains this formula:
=B4-TODAY()
How this formula works
In Excel, dates are simply serial...

To create a dynamic date list, you can use a formula that increments a start date to create and display additional dates. In the example shown, the formula in B5 is:
=start+ROWS($B$5:B5)-1-offset
where "start" is the...

To calculate a person's age from their birth date, you can use the YEARFRAC, INT, and TODAY functions. In the generic version of the formula above, birthdate is the person's birthday with year, and TODAY supplies the...

Note: Excel has several built-in data validation rules for dates. This page explains how to create a your own validation rule based on a custom formula when you want more control and flexibility.
To allow only a date...

T calculate the number of days between two dates you can simply subtract the older date from the newer date. The result will be an integer that represent the days between dates. In the example shown, the formula in D6...

To check if a date is within the last n months of today's date, you can use a formula based on the AND, TODAY, and EOMONTH functions. In the example shown, we are checking for dates in the last 6 months. The formula...

To add a date stamp in a workbook to indicate a "date last updated", you can use the TEXT function. In the example shown, the formula in C5 is:
="Last update: "& TEXT(B5, "ddd, mmmm d, yyyy")...

To highlight dates that are "past due" you can use a conditional formatting rule that checks if the variance between two dates is greater than a certain number of days. In the example shown, three conditional...

To calculate the number of workdays remaining in a month, you can use the NETWORKDAYS function. NETWORKDAYS automatically excludes weekends, and it can optionally exclude a custom list of holidays as well. In the...

To calculate the number of working days in a year, you can use the NETWORKDAYS function. NETWORKDAYS automatically excludes weekends and holidays if they are provided. In the example shown, the formula in E5 is:
=...

To sum sales in the last 30 days by an id (like name, initials, region, etc.) you can use the SUMIFS function together with the TODAY function. In the example shown, the formula in G5, copied down, is:
=SUMIFS($D$5:$D...

If you need to display the current date in a worksheet, you can use the TODAY function. This date will update whenever the worksheet is recalculated or opened.
Here's how the formula works:
The TODAY function takes no...

To determine invoice status (i.e. paid, open, overdue), you can use a nested IF formula and the TODAY function.
In the example shown, the formula in G5 is:
=IF(F5=0,"Paid",IF(TODAY()<C5,"Open...