Fatal error: Uncaught TypeError: strtotime(): Argument #2 ($baseTimestamp) must be of type ?int, string given in /in/LkYsh:3
Stack trace:
#0 /in/LkYsh(3): strtotime('-7 days', '2012-12-31')
#1 {main}
thrown in /in/LkYsh on line 3
Process exited with code 255.