Selecting pivot in sorted array.

[infantheartlyjes]

Hi folks,
I'm having 200,000 records those are sorted by date. Now i want to insert one back dated record as order. If i using quick sort to insert back dated record inside the file, How to select pivot element ?

for e.g. my records are like this.
0
1
2
4
5
3

How can i sort this using quick sort? How to select pivot element?