Sean Korzdorfer tweeted a link to a new OmniFocus Applescript that he wrote that deletes tasks that were not created in the last 14 days. I like the idea, but my brain can fail me at times, so I modified it to provide me a little more security.
-- prune_old_omnifocus
-- Created by: Sean Korzdorfer
-- Created on: 05/10/13 13:14:39
-- Modified by: Jered Benoit
-- Modified on: 20130510 1636
--
-- Just select a project and run.
--
-- CAUTION: This script deletes tasks. Be careful
tell application "OmniFocus"
-- Set the number of days old a task can be before deletion.
display dialog "Number of days old a task can be for deletion?" default answer "14" buttons {"Cancel", "OK"} default button 2
set daysPrevious to (the text returned of the result) as string
-- Last Chance
display alert "This deletes tasks!" buttons {"Whoa Nelly!", "Scorched Earth"} default button 2
set LineInSand to (the button returned of the result) as string
if (LineInSand is equal to "Whoa Nelly!") then
error number -128
else
set killDate to (current date) - (daysPrevious * days)
tell front window
try
set theTrees to selected trees of content
if (count of theTrees) set theTrees to selected trees of sidebar
end if
if (count of theTrees) return
end if
set theSelection to value of item 1 of theTrees
set theTasks to every flattened task of theSelection
repeat with theTask in theTasks
if creation date of theTask is less than killDate then delete theTask
end repeat
end try
end tell
end if
end tell
