In early March [1] we ran a survey to understand what effect it would have on developers to remove the since parameter and If-Modified-Since header support for timeline methods. The feedback from this survey and the continuing discussion indicates we can remove these parameters and reap the performance benefits without a large impact to developers.
The since_id parameter is immensely more popular for timeline methods and will be our recommended method for downloading timeline updates into the future. The removal of the parameter and header will not break any functionality. Rather, you will notice that unfiltered feeds will be returned. From the application's perspective, it will appear as if the since parameter or If-Modified-Since header are ignored. Please use the next few days to update your application to use the since_id parameter if it is currently using since/If-Modified-Since. This deprecation will happen when the deploy hits our server in the middle to end of the week. 1. http://groups.google.com/group/twitter-api-announce/browse_thread/thread/68f2667f4e9842aa?hl=en Thanks, Doug Williams Twitter API Support http://twitter.com/dougw
