The code doing that conversion is bugged as it results in integer division rounding up. So 31000 ms becomes considered as >.5 a minute, which is rounded up to 1 minute. So even watching the status time on the console from fresh start up, you can see it counts improperly 28s, 29s, jumps to 1m30s, 1m31, ... , 1m59s, and then back to an even 1 m, 1m1s, etc.