|String_Expression||String expression for exact date or relative date as described in date filters.|
DateParse('Dec 31 2012')
DateParse('1 month ago')
See example report Open issues trend in our demo account. The report uses measures report start date and report end date with a similar formulas to set explicit start date and end date for the report. Those dates via measures report start date, and report end date is used for several calculations, including setting the visible period in the report, calculating guideline, etc.