If you need to test two dates to see they both have the same month and year, you can do so with a simple formula that uses the MONTH and YEAR functions.
How the formula works
In the example, the formula in cell D6...

To generate a series of dates by year, you can use the SEQUENCE function together with YEAR, MONTH, and DAY functions. In the example shown, the formula in E5 is:
=DATE(SEQUENCE(12,1,YEAR(B5)),MONTH(B5),DAY(B5))...

If you want to test whether the year of a certain date is a leap year, you can use a formula that uses the MONTH, YEAR, and DATE functions.
In the example shown, the formula in cell C5 is:
=MONTH(DATE(YEAR(B5),2,29...

To filter data to include data based on dates, you can use the FILTER function with one of Excel's date functions. In the example shown, the formula in F5 is:
=FILTER(data,MONTH(date)=7,"No data")
where "...

If need to generate a dynamic series of dates with a formula that increase by one year from a single start date, you can do so with a formula that uses the DAY, MONTH, YEAR, and DATE functions.
How the formula works...

If you want to calculate the fiscal quarter from a date, and the fiscal quarter starts in a month other than January, you can use a formula based on the CHOOSE function.
Note: if you just need to calculate a "normal"...

If you need to get the month name (i.e. January, February, March, etc.) from a date, you have several options depending on your needs.
Do you just want to display the month name?
If you only want to display a month...

To sum data by month, ignoring year, you can use a formula based on the SUMPRODUCT and MONTH functions. In the example shown, the formula in H6 is:
=SUMPRODUCT((MONTH(dates)=3)*amounts)
The result is a total of all...

To add a given number of years to a date, you can use a formula based on the DATE function, with help from the YEAR, MONTH, and DAY functions.
In the example shown, the formula in D5 is:
=DATE(YEAR(B5)+C5,MONTH(B5),...

To generate a dynamic series of dates with a formula that increases by one month from a single start date, you can use a formula based on DAY, MONTH, YEAR, and DATE functions.
How the formula works
In the example, B6...

To get a fiscal year from a date, you can use a formula based on the YEAR and MONTH functions. In the example shown, the formula in D5 is:
=YEAR(B5)+(MONTH(B5)>=C5)
How this formula works
By convention a fiscal...

If you need to extract the month from a date, you can use the MONTH function. In the generic form of the formula above, the date must be in a form that Excel recognizes as a valid date.
Here's how the formula works:...

To count the number of birthdays in a list, you can use a formula based on the SUMPRODUCT and MONTH functions. In the example shown, E5 contains this formula:
=SUMPRODUCT(--(MONTH(birthday)=D5))
This formula counts...

To test two dates to see they both have the same month, you can do so with a simple formula that uses the MONTH function. In the example shown, the formula in cell D6 is:
=MONTH(B6)=MONTH(C6)
How the formula works...

If you want to calculate the quarter (i.e. 1,2,3,4) from a date, you can use the ROUNDUP function together with MONTH.
In the example shown, the formula in cell C5 is:
=ROUNDUP(MONTH(B5)/3,0)
How this formula works...