Why is 31st October special for Indian cricket?

October 31 has been a very special day for Indian cricket. On this day MS Dhoni and Chetan Sharma created history on the cricket field.
MS Dhoni played an unbeaten innings of 183 runs in 145 balls against Sri Lanka in 2005. This is his best score till date. Dhoni hit 15 fours and 10 sixes in this innings.   
In the 1987 World Cup, Indian fast bowler Chetan Sharma also took a hat-trick against New Zealand in Nagpur on the same date. He took all three wickets while bowling. This was India's first hat-trick in the World Cup.