When you click on the calendar to extend your rental, most times the first available date to select will be a day or two after your current hire is due to end (excluding weekends as we don't post on a Sat / Sun). This is because our booking system always allows extra time in between bookings to allow for us to process returns / check slings over etc. In the case of an extension, you just get to keep hold of the sling for that extra day or two for free!
The two days following your current hire end period (and all Saturdays and Sundays) will be greyed out. If it is greyed out further into the future than this then it is booked out already and you need to return the carrier by the last date of your hire period to enable us to fulfill subsequent orders.