Regular Delta-Wye Transformer VS -30 Degree Phase Shift Transformer

True or false?

"A regular delta-wye transformer (probably most common type TX in low voltage distribution ) provides a phase shift between primary and secondary of +30° WHEREAS a Harmonic mitigation transformer like the Type THR 30-Degree Phase Shift by Eaton provides phase shift between primary and secondary of -30 °."

I am working on a harmonic mitigation scheme that uses NEG -15° phase shift , POS +15 ° phase shift , NON (or zero) ° phase shift and +30° phase shift transformers. The calculations look good on paper but i want to make sure i can get +30° and -30° shifts. I know -15° and +15° are commercially available.