HI ,

After update to joomla 3.7 i have issue with calendar extra field and my site Goes Down and showing error belwo .

"ERROR DateTime::__construct(): Failed to parse time string "

Please consider to attached file .

Joomla 3.7.3
K2 2.7.1
Php 7.1 and 7.0

imgur.com/a/YMgrK

Hello,
Can you paste the entire PHP error?
It might show up if you enable error reporting and set it to development.