String to date conversion in SWQL

Is it possible to convert a string value to the date format with SWQL somehow?

I have some metrics from custom poller:

CurrentValue Caption

"CurrentValue" contains a date in MM/DD/YYYY format (actually a string value), and I want to compare it with the current date minus 180 days.
Comparison is not working with this query, and I think because "CurrentValue" type is not a "date":

SELECT UDCP.CurrentValue, UDCP.Node.Caption

FROM Orion.NPM.CustomPollerAssignment UDCP

WHERE Displayname = 'Battery_last_test'
    AND CurrentValue NOT LIKE 'Unknown'
    AND CurrentValue < ADDDAY( -180, GETDATE() )

It pops timeout error.

Found some info about DateTime function, but I can't make it work:

So I'd like to convert it to the date type before comparison. Is this possible?