Just a Tech question (and who doesn't love tech questions?)

Does anyone know of a heart rate monitor that specifically does this: Say your target HR is a given band, perhaps 115-125.

I just want a display that shows **total elapsed time, inside, that band**.  Thus, the stopwatch only advances, if, you are in the target band.

I realise any advanced watch includes a file of your HR over time; of course you could calculate time in any band afterwards.  What I'm saying here is, I'm looking for a simple live display of elapsed time-in-a-band.

Can anyone remember seeing this particular function on a watch?  Thanks!

I lean towards garmin FWIW. The function I describe is not on my beloved garmin 401, nor my polar (it's that cheapest polar).

Anyone remember seeing this - thanks!!

Further ... it appears this function is usually referred to as **time-in-zone** in advertisese. That may help others in the future looking for the feature. It does appear that a number of the Timex watches offer "time-in-zone", thanks to BISB below for the pointer.