As part of the recently-announced year-end event for Pokemon GO, the time period to catch Holiday Pikachu has been extended. Originally scheduled to last until December 29, these limited-edition Pikachu can now be found through the afternoon of January 3, 2017. Developer Niantic recently confirmed that a Raichu that evolves from Holiday Pikachu will still be wearing a festive hat in Pokemon GO. In addition, both will keep the hat permanently even after January 3.
Holiday Pikachu’s duration in Pokemon GO has been extended
Pokémon Blog 
One thought on “Holiday Pikachu’s duration in Pokemon GO has been extended”