What do you mean by time changing value? You might want to try Parse, parse is open source and can be installed on a server, or you can use one of the services that offers a free space with Parse already installed. I personally use back4app.com for my Android apps, it is simple and free and does the job. And they have paid packages as well.
Definitely check out deepstream.io. :)
Sandeep Panda
co-founder, Hashnode
Take a look at this discussion.