Imitating streaming data when markets are closed?

Is there a way to imitate streaming data while markets are closed? I would like to be able to develop my algo with streaming data but usually can’t during market hours. Being able to play back a day, or even an hour, of 1min bars would be great for testing.

What I do is log all the stream messages into a log file. When I test after hours, I loop through the log file to read the log message as a stream.