Wrong Leap Year Calculation

[tim-scherer]

Subject of the issue

• The leap year calculation yields that 2022 is a leap year; but next leap year is 2024.
• As a result of this, epoch time calculation error is 86400 s (24 h) wrong.

Your workbench

SparkFun_u-blox_GNSS_Arduino_Library](https://github.com/sparkfun/SparkFun_u-blox_GNSS_Arduino_Library Library V2.2.0

Steps to reproduce

The error is located in the calculation perfomed in

SparkFun_u-blox_GNSS_Arduino_Library/src/SparkFun_u-blox_GNSS_Arduino_Library.cpp

Line 16124 in 6eea877

DAYS_SINCE_MONTH[((uint32_t)packetUBXNAVPVT->data.year - 1970) & 3][(uint32_t)packetUBXNAVPVT->data.month] +

and

SparkFun_u-blox_GNSS_Arduino_Library/src/SparkFun_u-blox_GNSS_Arduino_Library.h

Line 625 in 6eea877

const uint16_t DAYS_SINCE_MONTH[4][16] =

Expected behavior

2022 is not a leap year

Actual behavior

DAYS_SINCE_MONTH[((uint32_t)packetUBXNAVPVT->data.year - 1970) & 3][(uint32_t)packetUBXNAVPVT->data.month] results as a leap year

[PaulZC]

Hi @tim-scherer ,

Wow. Thanks for reporting this! That gremlin has been in there for a long time... But I guess only appeared on Tuesday...

We'll fix this in the next release.

Best wishes,
Paul

[tim-scherer]

Hi @tim-scherer ,

Wow. Thanks for reporting this! That gremlin has been in there for a long time... But I guess only appeared on Tuesday...

We'll fix this in the next release.

Best wishes, Paul

This could be a fix, changing order of array (idx 0 to 3):

[PaulZC]

The corrections are in the release_candidate branch if you would like to test them?

Please see this commit for the changes. (I updated the examples too.)

[tim-scherer]

Thanks a lot for the fast reply and the quick fix. Seems to work fine 👍

[papillon81]

Confirmed working. Noticed the same 24h delta today. :)

[PaulZC]

Hi @tim-scherer / @papillon81 ,

Thank you both. I will release v2.2.5 in a few minutes.

Best wishes,
Paul