Andrej Kolar writes:

http://forum.naviter.com/threads/1078-IGC-Speed-and-Distance-task-script

You need the "Speed task - no handicap" script:
http://forum.naviter.com/attachment.php?attachmentid=101&d=0

It should be pretty self explanatory. You need to set a task (any task), you
MUST define task time. You need to do that in Edit > Day properties > Task
Options.

You must use the correct script

You MUST set task type to "Assigned Areas Task - AAT"

You MUST set task time.

It is always considered to be "Minimum task time". Anyone that flies less than
that time get scored by this time. Anyone that flies longer gets scored by his
actual time.