"no native desktop app (Linux or otherwise) is available the service at least at present" so #surveillance is obligatory (see #wikileaks #vault7 for instance) https://www.omgubuntu.co.uk/2020/01/proton-calendar-beta-release
Proton Calendar is a private calendaring solution from the makers of ProtonMail that uses end-to-end encryption of all events, titles and dates created.
omgubuntu.co.uk
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