Calendar doesn't show tasks and other module's dates (except events) if user date format is different from 'YYY-MM-DD'

there is an error in feed.php action, it doesn't correctly checks date formats leading to empty results

I've tested it on demo too

mentioned in merge request !856 (merged)

mentioned in commit e41378ed

mentioned in commit 67a57396

mentioned in commit 86cbaacb

Status changed to closed