There may be no need for you to upgrade! Check out the command reference for clock summer-time:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_command_reference_chapter09186a008017d030.html#wp1033365You can manually specify the start and end days or dates of DST in the configuration.
From Cisco's examples on that page:
The following example specifies that summer time starts on the first Sunday in April at 2 a.m. and ends on the last Sunday in October at 2 a.m.:
Router(config)# clock summer-time PDT recurring 1 Sunday April 2:00 last Sunday October 2:00
If you live in a place where summer time does not follow the pattern in the first example, you can specify the exact date and times. In the following example, daylight saving time (summer time) is configured to start on October 12, 1997 at 2 a.m., and end on April 26, 1998 at 2 a.m.:
Router(config)# clock summer-time date 12 October 1997 2:00 26 April 1998 2:00
