***This has been fixed in newer builds of DD-WRT - Check yours before continuing***
This never looks to be a problem since DD-WRT provides such extensive options. Unfortunately, unlike Tomato and OpenWrt, which do a good job, DD-WRT's approach is way off and completely wrong.
A Linux box can keep its time in either local time or UTC -- both are fine as long as the corresponding time zone info is presented. However, in DD-WRT, the time zone info is completely missing and instead of standard implementing used in almost all Linux distros, DD-WRT coins a weird scheme to setup(and keep) the time.
For example, 8AM PST(GMT-8) should be 4PM GMT, but a DD-WRT router would "think" the current time is 8AM GMT. Now if you change the time zone to EST(GMT-5), what will the router think? 11AM GMT!! Yes, that's after you've set all the "time zone" info in DD-WRT web management page. This is usually not a problem if you just want to use it as a router but for a Linux server, you definitely don't want to deal with any file created in future.
Now here is the fix:
