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...

This formula looks at one way to increment a number that is embedded in a text string. The purpose of this example to show how multiple functions can be combined to split, manipulate, and rejoin values.
In the example...

To join a date with text, you can use concatenation with the TEXT function to control the date format. In the example shown, the formula in E4 is:
="The date is "&TEXT(B4,"dddd, mmmm yyyy")...

To lookup the last entry in a table by month and year, you can use the LOOKUP function with the TEXT function. In the example shown, the formula in F5 is:
=LOOKUP(2,1/(TEXT($B$5:$B$13,"mmyy")=TEXT(E5,"...

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...

If you need to convert a date to a Julian date format in Excel, you can do so by building a formula that uses the TEXT, YEAR, and DATE functions.
Background
"Julian date format" refers to a format where the year value...

To pad week numbers (or any number) with zeros using a formula, you can use the TEXT function.
In the example show, D5 contains this formula:
=TEXT(WEEKNUM(B5,21),"00")
Which returns the string "07".
How...

To convert numbers into text values, you can use the TEXT function.
In the example shown, the formula in C5 is:
=TEXT(B5,"0")
Background
Normally, you want to maintain numeric values in Excel, because...

To convert a normal Excel date into yyyymm format (e.g. 9/1/2017 > 201709), you can use the TEXT function.
In the example shown, the formula in C6 is:
=TEXT(B6,"yyyymm")
How this formula works
The TEXT...

To calculate and display the days, hours, and minutes between two dates, you can use the TEXT function with a little help from the INT function.
In the example shown, the formula in D5 is:
=INT(C5-B5)&" days...

If you want to use conditional formatting to highlight dates that are in the same month and year as another date, you can use a simple formula based on the TEXT function.
For example, if you have dates in the range B4:...

To pad a number with zeros, you can use a simple formula based on the TEXT function. To pad with a variable number of zeros, you can add the REPT function.
In the example show, the formula in D6 is:
=TEXT(B6,"...

To perform a partial match (a substring match) against numbers, you can use an array formula based on MATCH and TEXT.
Background
Excel supports the wildcard characters "*" and "?". However, if you use wildcards with a...

To lookup the first entry in a table by month and year, you can use and array formula based on the INDEX, MATCH, and TEXT functions.
the LOOKUP function with the TEXT function. In the example shown, the formula in F5...

If you need to convert dates to text (i.e. date to string conversion) , you can use the TEXT function. The TEXT function can use patterns like "dd/mm/yyyy", "yyyy-mm-dd", etc. to convert a valid date to a text value....