DatePicker With Time

I am using CJuiDatePicker in my project…I have field named billdate with datatype "datetime" so i want to add time with this datepicker…

I want to use it but i am not able to do as i don’t know where to add the code and how to use it??

If anyone having idea about this then give me solution…

There are (at least) these 3 extensions:

I am using third link which You mentioned above…but i am not aware that where i have to add code to use this with datepicker…