One of the Google Earth API Demos shows how to display historical imagery, hide and show the timeline bar, and set the current date for the display. The demo is available at http://code.google.com/apis/ajax/playground/?exp=earth#time_and_historical_imagery_ui
However, if the current date is set to a time for which there is no imagery, the closest available imagery is used. For example, if the date is set to 2005, but there are only images from 2003 and 2009 then the ones from 2003 will be used.
How can I find out, via the API, what the actual date of the imagery shown is? It doesn't need to be an exact date, but knowing the year is important, and knowing the month would be brilliant.
Is this possible?
You'll note that in the UI of the time slider, there are little tick marks for each available date for which there is historical imagery for the current view.
As you change the camera or lookat, different imagery may become available. As you zoom in, for example, more or less imagery may become available.
To programmatically get a list of the dates associated with these tickmarks, you can call:
ge.getTime().getControl().getAvailableImageDates()
This will return a KmlObjectList of KmlTimeStamps which you can iterate through.