4.2. Standardized Time Zones

Why are standardized time zones needed?

• For improved interoperability: Calendar applications need to have a reliable list of time zones and their associated rules in order to avoid the following common problems:

  • Consuming unknown time zones.

  • Consuming known time zones with identical TZIDs but different rule.

• Calendar applications need to have means of updating time zones and all affected data (i.e. previously created recurring meetings.) in an efficient and correct manner.

• Having standardized time zones would open the door to using time zones by reference rather than by value (Sending only the time zone id rather than the whole time zone with its rules). This could potentially help applications where bandwidth usage is important such as mobile devices.

• Any other non-iCalendar products having to deal with time zones could also benefit from it (Operating systems, java…​).