Run window message 'Identical line'
I/flutter ( 7764): myDate.day is 16
I/chatty ( 7764): uid=10079(com.homemy.myspriteapp) Thread-78 identical 17 lines
Presumably your code that prints myDate.day is 16
has run multiple times in a short space of time so rather than fill the output up, it's been folded into that message.
Whether this is bad depends where the code is; if it's somewhere that is expected to run many times (like inside a loop) then of course it's fine. If it's somewhere you would not expect to execute multiple times, you may be able to understand why it is by adding a breakpoint and reviewing the call stack.
After two hours of debugging I can tell you not to underestimate that message. In my case, printing a dynamic value in a cycle, I got that message. I only found out after that I had a looping cycle. In fact, when I debugged the first cycle where I printed a string, there was an anomaly, that is, it stopped randomly without reason. This made me understand that it was the instructions already executed that created this anomaly even before I passed from the cause (loop of second cycle).