How come my Christmas Cactus won't bloom? Last year it didn't bloom until end of January and now it's the 2nd week in February and it still hasn't got one little bud??

If temps are too warm, possibly not watered correctly or in artificial lighting for long periods, they might not set buds.
Feed lightly throughout spring and summer, none when you see buds forming.
In the fall, keep it cool temps(55-65 degrees) plus the shorter daylight hours should set buds.