I use this functionality all the time. It would be a great improvement to the UX.

Events can be duplicated on the web, but not in the Android client. this is quite important. I can't make duplicate events while out and about.

As with other calendars I use, I just start typing the title of the similar event e.g., blood test, and the app suggests the details (title, location, travel time (another missing feature), etc.) from a previous entry with the same title to create a duplicate. I can then amend the time and date as required for the new event. A button could also be added to an existing event to "create duplicate" (different people do things in different ways).

This is one of a number of features that is currently preventing me from switching to use Proton Calendar.

Shortcuts for copy and paste would be really appreciated, either alt-drag as other suggested or ctrl+c / ctrl+v. I used to use thunderbird's calendar features, and it really is the only functionality I'm missing, but it's missing a lot.

Duplicate of https://protonmail.uservoice.com/forums/932842-proton-calendar/suggestions/42699347-duplicate-an-existing-event
Please move your votes there, as there are more votes

This is a critical feature for productivity.

I came here to ask for the same feature:

It would also be time-saving to be able to hover the mouse over the start or end time of an event and be able to drag the top or bottom of this event to increase its duration automatically.

It would be very useful to be able to duplicate/copy an event, especially if the event has already a lot of configuration (description, notifications, etc.)

It's basic functionality that I'm shocked is not included already.

copy and paste a necessity! Pretty much a deal breaker. Everything else looks good.

alt drag for copy and paste a deal breaker. Need to have this capability.

Add a button to duplicate an event in Proton Calendar

Yes, please!

Ditto, the one major feature missing for me!

For those of you that work rotating schedules, see my idea about integrating rotating work schedules! Duplicating events is a much easier way than having to input each instance individually, but take it a step further, and be able to schedule your entire work schedule for the year in one fell swoop. Enter days on, enter days off (5 on, 2, off. 5 on, 3 off, repeat) and boom. Done. It would set ProtonCalendar apart from Google Calendar.

Or be able to link to a shift worker app that automatically repeats the rotation

Yes! Biggest thing I need for shift work on rotation

I agree. It would be a lot more efficient if I could duplicate and edit the event rather than start over.

Could a duplicate function be added for existing appointments so that it can be edited for future appointments that are not on recurring/repeat basis. This would save time entering person, location, etc data.

At least from the web browser UI, it would be convenient to be able to make a copy of a calendar event (and subsequently customize the copy) by clicking on the event. As of this writing, only Delete/Edit are shown.

Eventually, this would be nice to have such functionality for the Android/iOS applications as well.