I mean that if I want to send 1BTC tomorrow 12pm for someone, but I will have no opportunity to get to my eWallet, than is it possible to schedule the transaction?
This has been asked of EWallet providers but the feature has not been offered by any yet. You could probably contract with an escrow provider at a low fee to do this.
The bitcoin protocol has an nLockTime which would presumably allow this however no clients currently support it.