How would I take a date field and subtract 30 days to show the month prior to the original date

Question

I have records that are modified each month. The site is used to display the previous month's information. However, to make sure that the information is correct, I want to use the date the information is modified as the original date and retrieve the month prior to that date. Eventually I want to use the previous month to format the label dynamically.

For example, if the records are updated on March 10, 2013, I would be displaying the data from February so I want the label to say "February 2013."

Any assistance is greatly appreciated!

Answer 1

It's going to be a great, big messy calculated column, but it can be done. There's probably better ways to do this but nothing I know how to do offhand.

New calculated column, type of Single Line of Text (String):

=IF(MONTH([MyRecordUpdated])=1, "December "&YEAR([MyRecordUpdated])-1,
IF(MONTH([MyRecordUpdated])=2, "January "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=3, "February "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=4, "March "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=5, "April "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=6, "May "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=7, "June "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=8, "July "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=9, "August "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=10, "September "&YEAR([MyRecordUpdated]),
IF(MONTH([MyRecordUpdated])=11, "October "&YEAR([MyRecordUpdated]),
"November "&YEAR([MyRecordUpdated]))))))))))))