There are three reasons why a shift your were invited to is unavailable:
1. Accepting the shift may lead your to be working too many consecutive hours
If accepting a shift invite would put you over 18.5 consecutive hours of confirmed shifts, you will be prevented from accepting that shift.
2. Accepting the shift would overlap with another confirmed shift
A shift to which you are invited may be unavailable if that shift overlaps with an existing confirmed shift.
3. Accepting the shift would put you into overtime and the facility does not allow overtime
You can work overtime with ESHYFT, and you can do so with shifts you're invited to, if the facility allows overtime nurses. If the facility does not allow overtime, you will not be able to accept the shift invite.
If the shift is unavailable due to one of these reasons, it will be marked accordingly in the "INVITED" tab.