Date and Time Picker broken

Date picker and time picker are erroring out on the front end and the booking calendar is taking A LONG TIME to get through to the services.

Here is from the debug console

[28-Sep-2017 17:58:13 UTC] PHP Notice: Undefined index: +5 minutes in /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Helper/HoursBefore.php on line 28
[28-Sep-2017 17:58:13 UTC] PHP Notice: Undefined index: +5 minutes in /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Helper/HoursBefore.php on line 102
[28-Sep-2017 18:00:09 UTC] PHP Fatal error: Uncaught exception ‘Exception’ with message ‘wrong date 17171717-09-2828’ in /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Func.php:88
Stack trace:
#0 /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Action/Ajax/CheckDate.php(128): SLN_Func::filter(‘2828 Sep 171717…’, ‘date’)
#1 /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Action/Ajax/CheckDate.php(56): SLN_Action_Ajax_CheckDate->getDateTime()
#2 /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Action/Ajax/CheckDateAlt.php(85): SLN_Action_Ajax_CheckDate->checkDateTime()
#3 /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Action/Ajax/CheckDate.php(30): SLN_Action_Ajax_CheckDateAlt->checkDateTime()
#4 /nas/content/staging/nwc/wp-content/plugins/salon-booking-system/src/SLN/Plugin.php(210): SLN_Action_Ajax_CheckDate->execute()
#5 [internal function]: SLN_Plugin->ajax(”)

I’m currently rolling back to an older version of the plugin but I’m concerned I won’t be able to use it anymore

The page I need help with: [log in to see the link]