CCCWC February competition voters’ comments on Clue no. 13

A clue to BISSEXTILE.
3 comments refer to this clue (from 3 competitors, 0 others)

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Comments on the clue

1.	The pun is a bit specialised
2.	Wordplay-shmwordplay. The reference to Fourier transforms (and hence periodicity) doesn't lead one neatly to the solution.
3.	What is a transform in the context of BISSEXTILE?