Using gmdate & gmmktime in reports while uc_reports uses simply date & mktime

Hello everyone,

Thanks for this awesome module.
Faced issue of Seller's sales reports displaying one month difference while calculating sales.
Found http://drupal.org/node/944878 for Drupal 6, but not resolved.

I am failing to understand the reason behind usage of gmmktime and gmdate instead of simple date/mktime functions. In Ubercart module, even uc_reports is using mktime and date functions.

Please help/guide by explaining the reason.

Thanks & Best regards,

Tajinder Singh