This is not the determinant -- the determinant is what year's choice benefits you give. If you use choice benefits from status earned this year (which Delta calls the 2018 Medallion year), the gifted status will be valid through 1/31/19, regardless of when you make the gift.

If you want to use choice benefits from status earned based on 2016 flying (the 2017 Medallion year), the gifted status will only be valid through 1/31/18, which isn't worth much. So in that case it would be better to wait until you have hit 75K MQMs this year and can gift status that will last longer, and use the 2017 choice benefit selection for something like RUCs or miles that won't expire so soon.