How to apply DATEVALUE to column

I have two columns with extracted date values. I want to add those two values together and apply to the whole column. The data looks like this:

AM     AN          AO      AP          AQ date    time        year    day value   time value Oct 12  14:15:00    2020    #N/A        0.59375

I want to concatenate or join the values of AM and AO, pass to DATEVALUE, and apply to the whole column. Current the formula for AP is:

=DATEVALUE(concatenate(AM2,", ",AO2))

But I cannot apply this using ArrayFormula.

I've tried using CONCAT, JOIN, and & on the two values without success, e.g.

=ArrayFormula(DATEVALUE(AM2:AM & AO2:AO))