ISS flight schedule of russian spacecrafts was changed since the first launch of Progress MS new generation cargo vehicle was shifted from November to December.
“Because of this shift the shole program of manned and cargo vehicle launches to the ISS for the first half of 2016 was changed.
The first launch of Progress MS cargo vehicle was shifted from November 21 to December 21. Due to that next Progress MS will be launched on March 31 instead of February 2.
The launch of third Progress MS initially planned for June will take place on July 4.
Manned spacecrafts launch schedule also changed because before the first launch of Soyuz MS spacecraft two Progress cargo vehicles are to be launched for safety reasons. Due to that it will be Soyuz TMA-20M to go to the ISS on March 19 instead of Soyuz MS.
Due to the launch dates shift the dates of landing also changed. For example Russian cosmonaut Yuri Malenchenko, American astronaut Timothy Kopra and British astronaut Timothy Peake who will go to space on December 15 will stay onboard the ISS longer coming back on June 5 instead of May.