Whilst creating customer scenarios for the forthcoming leap second event this June, a rather surprising issue has come to light.
BeiDou uses a different "day number" for the date to apply the leap second, compared with GPS and Galileo. GPS and Galileo use 1-7 as week day numbers, and BeiDou uses 0-6.
We discovered that this fact has been missed during development of some BeiDou enabled receivers. The result is that the leap second may be implemented a day early on GNSS engines that are tracking the BeiDou constellation. The error presents itself when the receiver is running on the BeiDou constellation alone, and when the date is June 29 of this year.
Read the full article on the BeiDou leap second issue in GPS World.