deadsea - 10:26 am on Jun 23, 2012 (gmt 0)
The first hour that looks down is Jan 19th at 1900 GMT. It drops hourly over the next 4 hours. It is down to its final level by 2300 GMT.
Here is the graph (in EST): [i.imgur.com...]
Edit: I realize I labeled 1900 GMT as 1800 GMT on the graph.