We are using this set up as a simple booking system for rooms. We have used the timeframe module to give a minimum of two days booking, when that is triggered this is the message we get.

Notice: Undefined index: en in agres_timeframe_api_get_restriction_message() (line 224 of /home/sites/MyURL.co.uk/public_html/sites/all/modules/agreservations/agres_timeframe/agres_timeframe.api.inc).
Notice: Undefined index: en in agres_timeframe_api_get_restriction_message() (line 235 of /home/sites/MyURL.co.uk/public_html/sites/all/modules/agreservations/agres_timeframe/agres_timeframe.api.inc).
Notice: Undefined index: en in agres_timeframe_api_get_restriction_message() (line 245 of /home/sites/MyURL.co.uk/public_html/sites/all/modules/agreservations/agres_timeframe/agres_timeframe.api.inc).
The selected period is not compatible with a reservation restriction from 23.10.2012 to 31.12.2015. During this period you can only make reservations with a minimum length of 2 days. Please change your reservation to this time.