how can i mention current time on bill
Only by using a custom field
Why would you want to indicate the time on an invoice?
Most accounting systems work on a period and treat all transactions dated the same day as equivalent - there is no order
YES, but i need to mention time on my sale invoice
Then create a custom field for the sales invoice called Time and enter the time when you create the invoice
The time cannot be calculated and entered automatically - after all, you might be entering an sales invoice for a sale that made yesterday or a week ago