| Horde_Timezone | Base class for loading, parsing, and working with timezones. |
| Horde_Timezone_Exception | Exception class for the Horde_Timezone library. |
| Horde_Timezone_Rule | Class representing a set of "Rule" timezone database entries of the same name. |
| Horde_Timezone_Zone | Class representing a set of "Rule" timezone database entries of the same name. |