c# - Windows Phone Contacts and Date Modified -

is there way can know last modification date of contact or when added ? because in application need example synchronize , newly added contacts , that. isn't there unique identifier contact or @ least account ?

there no unique identifier , no properties modified date or creation date.

i suspect intention try , protect user privacy discouraging building of apps track contact information.

the best can done use combination of fields unlikely change (i.e. name & dob) , use these identifying factor. store hash of information against id , if hash doesn't match when checked in future you'll know has changed.