July 21, 2012 - Multiple graph display issue

During deployment of our latest release, some members of the public noticed problems displaying graphs of instantaneous values for multiple sites when a period of less than 120 days is requested. The following error message occurs:

Date::Calc::Delta_Days(): not a valid date at /www/htdocs/nwisweb/lib/NwisWeb/Support.pm line 501.

Removing the &period=xx where xx is the number of days from the URL will cause the error to disappear but may show different results than expected. We consider this a serious problem and it will be addressed early during the next workweek.

No other problems have otherwise been noted with the new release, which is proceeding. We apologize for the error and inconvenience while we remedy this problem, and will notify you when it has been corrected.