Missing recurring event settings: Every month/year on the xth Saturday of <month>

[StoppingBuck]

The current event creation on pim.etesync.com seems a little limited in ways of customizing recurring events, compared to e.g. Thunderbird or Google Calendar.

Specifically, I have an event which happens "on the last Saturday of each month", but the current settings only allow "Monthly every X Saturday", which doesn't really work since some months have three Saturdays, others have four and some might even have five.

Same issue seems to occur with annual events happening "on the last Saturday of February", which also isn't supported at the moment.

Thunderbird supports a host of different recurrence options that Etesync web could use, like

For monthly: "The First/Second/Third/Fourth/Fifth/Last X" (combined with "Mon/Tue/Wed/Thu/Fri/Sat/Sun/"Day of the Month") which is notably different from saying "Every 1, 2, 3, 4, 5... Saturday", like Etesync Web currently does.

For annually, you can set the same options as for monthly, but only for a specific month - like February.

Luckily for me, since Thunderbird supports these recurrence options, I can just set my recurring events in Etesync using Thunderbird. But it would be nice to have the web interface support them as well :slightly_smiling_face: