1. Time decoding is not bit rotating (by 4), but you can use

   [(e&0xf)*10+(e>>4) for e in data[1:8]]

Please see this multiplication by 10.

1. TZ decoding must be done before time decoding. So,

   tz='+' if data[7]&0x08: tz='-' data[7]&=0xf7

Except these points, this problem was indeed fun. ^^