Please help us by providing the following info. Before posting please also check the pinned "Known issues" threads and make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/
Steps to reproduce
1. Create an ICS file containing (among others) appointments in the future (i.e. later than toda)
2. Inport that ICS file into OwnCliud calendar app
3. See if the appointments in the future are visible in the calendar app or not.
All appointments from the ICS file should be visible in the canlendar app.
All appoimtments are visible until (and including) today. Appointments in the future (from tomorrow on and later) are missing.
Operating system: Raspbian
Web server: nginx
PHP version: don't know
ownCloud version (see ownCloud admin page): 9.1.0. (stable)
Updated from an older ownCloud or fresh install: fresh install
ownCloud log (data/owncloud.log, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808): n/a
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption): n/a
Integrity status for oC9+
Login as admin user into your ownCloud and access http://example.com/index.php/settings/integrity/failed paste the results here. "No errors have been found."