Thought of a useful function to certain tasks.
Here's the situation:
You want to loop through a list of files in a directory but the files are not cleared out of the directory after processing. So every time your job runs, you want just the new files.
I thought a good solution to this problem would be to set up a list files task, and change the date settings to only grab files with a modified date of when the list files task last executed. But it turns out, while the last executed date/time is a variable on a task, you can't use it in the date checking field. It comes back with "invalid date" even though the formula parser displays a date/time like it will work.
As a workaround, I instead set a user variable immediately after the list files task ends, and use that in the list files date filter so that next time it runs it has a stored date to use.
I could think of other useful ways this could be used too not just with dates. You could actually adjust the file mask or do specific content search based on the previously run task. The workaround works, but is less elegant than simply referencing the task itself.