Timezones problem in Zoho CRM

Timezones problem in Zoho CRM

Here in the UK we have just moved from British Summertime to normal GMT, 1 hour difference, and all my customers' Zoho systems are now showing 1 hour later than the actual time.

I thought I had found a timezone setting that allowed for the time change, but apparently not.  There in no explanation whatsoever in the userguide on what all the different timezone options actually do.

Can you please tell me which timezone setting to use which will allow for the change automatically when we move from British summertime to GMT and back?  (or for that matter for any timezone where they move to daylight saving time for some of the year).

Or do we have to manually change the settings every time, twice per year???  Surely not?