I have downloaded the Time Manager plugin for QGIS. I have created a simple test file with only 4 points, with a date attribute showing YYYY-MM-DD, each point moving forward one day. Yet it tells me that the attribute selected for use as start time contains invalid data. What am I doing wrong?
How have you created the test file? Open your attribute table and have a look at how the data actually appears. If you used, for example, OpenOffice or Excel to edit a CSV file and make a date column, it may store the date in a different numeric format, even though it displays YYYY-MM-DD in the spreadsheet.
Works for me (QGIS 1.7.4, OSX 10.7) using data in a 'date' column like the one following (I entered the data manually within QGIS, as a text field):
date 2012-05-19 2012-05-20
Check whether you have extra spaces before or after your date entry, too.