Unfortunately the system cannot adjust for DST automatically, as not every country observes daylight savings time and even in the counties that do some states or regions ignore it, not to mention every country jumps at different dates.

You can manually adjust you system time on the following page https://www.kennelbooker.com/app/settings_overview.aspx 

The system will show you current time in footer of the web page

Its best to do this at the start of the day or at the end of the day if your pricing is based on the number of hours a pets stays on-site, as changing the time mid-way though the day can effect this calculation.