How to Correct the date on PM3 Logcard

[richfz1]

I have several months of workouts on a PM3 Logcard with the wrong year. Is there any way to correct the dates. I have not tried to upload them to my concept2 log. I'd rather fix them first if possible. Any suggestions?

Thanks in advance,

Rich

[Citroen]

It is possible, but it's not easy.

I don't have access to my notes right now.

The dates are all stored as binary coded decimal values within the Logcard data.

[richfz1]

Finally got back to this. I have a backup of the log card and I'm looking at it with a hex editor. Any information you could give on the format would be great otherwise I'll try matching the data against what the monitor shows to figure it out. Thanks.

[Citroen]

I've sent you a private message as I'm not sure Concept2 would want me to publish all the details of their date compression and workout encoding stuff in the open forum.

The date is basically a form of binary coded decimal mixed with integer binary in an overlapping bit string. So, for example 06:48 on 10th July 2017 will show up as 1111 1100 0010 1010 0111 0000 0110 0100 1000 for 10 07 0 6 4 8. The day of the month uses five bits for 1 to 31 (rather than 8 bits for tens and units). Those bits 1111 1100 001 are used to encode 2017 in integer binary.