DATESINPERIOD creating a Blank on Date

[n8ball]

I've been racking by brain on what would be causing the following. Here is my measure and the result below. Sum of NB$ doesn't have any blank dates. Date table is from 1/1/2022 to 12/31/2022. I'm getting the same result if I get rid of the CALCULATETABLE and dates in the past filter. I don't see any relationship errors between the Billings and Date table. Any guidance you can provide is appreciated. 

NB$ 12mo = 
CALCULATE (
    SUM ( Billings[NB$] ),
    CALCULATETABLE (
        DATESINPERIOD ( 'Date'[Date], MAX ( 'Date'[Date] ), -1, YEAR ),
        'Date'[DatesInThePast] = TRUE
    )
)

What the Blank?

[n8ball · Accepted solution]

Well, I figured it out. 
I had a separate Fact Table (not referenced by this measure) that had dates outside the dates contained in my date table. The blank date above was eliminated, once I filtered this other fact table to match my datae table range.