There are two “special fields” in Crystal Reports that allow you to print the date or the time of when the report file was last modified.  Any change to the design of the report should cause these fields to update. But Gordon Portanier of Crystalize in Canada just pointed out an apparent bug to me.  If a report has a subreport then the modification date and time update every time you open the report.

So say you saved 2 reports last night, one with and one without a subreport. They both had the special field “modification date” in the report header.   Then you open and run them both this morning without making any changes.  The one without a subreport will show a modification date of yesterday, which is correct.  The one with a subreport will show a modification date of today.   Every day you run a report with a subreport the modification date/time will show as if a modification was made today.  This behavior exists in all versions of CR that I tested – from v8.5 up through v12 (CR 2008)

I found an exception that I thought would lead to a workaround.  Say that last night you put the modification date into two places in the same report.  You put it into the subreport and also into the main report.  When you run the report today you will see two different modification dates for the same RPT file.  The one in the subreport will show yesterday but the one in the main report will show today.  I shared this with Gordon and he thought the subreport date would only change if the subreport was changed.  So I tested to see if a mod date in the subreport would pick up changes in the main report.  And Gordon was right.   So no simple workaround yet.