Based on the position in the English alphabetical order, three of the following letter- clusters are alike in some manner and one is different. Select the odd letter-cluster.

IDAY

IDAY  = I → (+5) → D → (-3) → A → (-2) → Y (THIS IS ODD)

SNJH  = S → (+5) → N → (-4) → J → (-2) → H

QLHF  = Q → (+5) → L → (-4) → H → (-2) → F

VQMK = V → (+5) → Q → (-4) → M → (-2) → K