On Fri, Jan 30, 2015 at 8:09 PM, <utahcbs at gmail.com> wrote: > Any idea what I am doing wrong? Probably nothing wrt the Datums. The 2100 has the "apply as soon as announced" leap second bug. There are some receivers. including the Z3812, that want to apply the leap second in March but the Z3801 is reported to be working correctly.