The hotel has amended their times slightly for the shuttle service, presumably due to the service being late on a few occasions. Here is the link:
http://www3.hilton.com/resources/med...dule_Aug17.pdf
The main hotel website reads as "Shuttle bus every 30 minutes. Peak times every 45 minutes".
Previously, the hotel website read as every 30 minutes (traffic permitting) and the times on the .pdf were given every 30 minutes.
Here is the timetable when the new service was launched, and which has now become superseded by the new timetable. The new timetable seems similar to the timetable before the new service was launched (one version of which is shown
here).