How to sync docs based on create time?

I have a phonegap-plugin based android group chat app, and I want to make user in the same group can sync message.but I only want to sync the message that created time posterior to the time that user join into group. so In my doc design, I have some docs like: group doc

Re: How to sync docs based on create time?

On Jul 13, 2015, at 11:10 AM, atom992 yangzijun...@gmail.com wrote: I have a phonegap-plugin based android group chat app, and I want to make user in the same group can sync message.but I only want to sync the message that created time posterior to the time that user join into group.