In T11809#199051, @deric wrote:

The rP3f2f81a1c8ab: Remove obsolete Calendar event date storage fields commit broke our phabricator setup.

#1054: Unknown column 'event.dateTo' in 'where clause' at [<phutil>/src/aphront/storage/connection/mysql/AphrontBaseMySQLDatabaseConnection.php:325]
PHP message: arcanist(head=master, ref.master=fad85844314b), phabricator(head=master, ref.master=bd3233d3ab0c), phutil(head=master, ref.master=e409df2720c2)
...

for fixing seems to be enough:

use phabricator_calendar;
alter table calendar_event add dateTo int unsigned NOT NULL;
alter table calendar_event add dateFrom int unsigned NOT NULL;