Hi ravi,

so many replies you received now i think you understood that attitude and approacjh is important before giving a call, I should tell that giving a call around 7-8 in evening also help as most people are out of office and not yet fully engaged in personal life so they listen to your call and respond. During office hours they are busy and even late evenning they dont want to get disturbed during their personal life so I think thats time you can target. It works for me.
Wishing you all the best.

Regards,
Shilpi