I had a requirement to send the notification to friends mobiles depending on the users time zones

The time zone issue doesn't seem to be relevant here - essentially are you asking how to send a message at a given time without using schedulers?
What do you mean by schedulers, and why don't you want to use one? A scheduler is just something that schedules something - which is by definition what you want to do - so I think you may not have explained yourself well.
Also, when you say send notifications to his friends, what sort of notifications? Are you talking about sending an SMS, and email?
If it needs to be push technology then you will have to schedule it in some way - even if you just check every (say) 15 minutes if anything is due. If it can be pull (e.g. when a friend logs in they are told it's Bill's Birthday then you don't need any sort of schedule, just a database record holding the relevant data.
Perhaps you can give us some more detail to help us to help you?