Check List item end date synchronously thanks for reply but i am not able to edit item or any thing with list item. so event receiver is not the way.
What you say about Timer Job.
How can I pass credentials to SharePoint 2010 people service? have u updated your code with referencing this two line also:
ls.ClientCredentials.Windows.ClientCredential = System.Net.CredentialCache.DefaultNetworkCredentials;
ls.ClientCredentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Impersonation;