Change Abbreviation::getMetazones to accept only abbreviation parameter
Add more tests for Abbreviation class
Timezones can be filtered by region
Improve Time filtering for #loadEntries
Add more tests for Timezone
Correctly add Metazones for Rails zones
Improve #findOffsets to use offsets for current period if no transitions are found
Add more tests for Rails
Remove some methods from ZoneInfo class
Types should always be symbols
toTime and fromTime should be optional
Add more tests
Add respective module methods
Improve TimezoneParser methods and add .isValid? method
Add tests for TimezoneParser