[Kst] possible to have timestamps when x-axis is index?

[Ryan Grice]

I'm graphing live data with a sample rate of about 500Hz.  KST handles
it great, however when looking through a whole days data it's easy for
me to lose track of the time frame I'm looking at.  I tried adding a
time vector using unix epoch time with "Interpret as C Time"  and
using that as the x-axis, but then the data is only plotted once per
second (Seems like all the Y data from that second shares the same X
resulting in vertical lines).   Is there a way to use index as the
x-axis and still show timestamps?  Or is there a way to use time as
the X-axis with millisecond resolution?

I read through the handbook and did quite a bit of searching but
haven't come up with a solution

Thanks
Ryan