You may be a bit late on getting your Christmas cactus to bloom, but give it a try. The Christmas cactus is a "thermo photoperiodic" plant. That means its flowers are affected by temperature (thermo) and light (photo) changes. Approximately 10 to 12 weeks before the time you want flowers, try to provide lower nighttime temperatures in the 55 to 65 degree range and dark nights uninterrupted by any light. You must provide the usual bright indirect light during the day. Reduce watering at this time, but not to the point of wilting. Just let the soil get quite dry before watering. If you can provide temps around 55 degrees, then the completely dark nights are less important. Do this for at least 6 to 8 weeks and you will see buds begin to emerge and the flowers will open a few weeks after that.

Note: Do not move or rotate your Christmas cactus while the buds are developing or they will drop off.

The closer you come to achieving these conditions, the more blooms you will get, but don't become a slave to these pre-bloom conditions. Well-established plants that have been in the same pot for a long time will often bloom without the cool, dark nights.