We are careful to use the yellow cedar, and not the red cedar down here - red won't last. The yellow comes up like a bush, instead of a tree, so ID is easy before you cut.
Old timers said to cut in Dec, Jan, and early Feb for the best posts - and to de-bark them as soon as practicable.
Yellow is more crooked - but lasts
Hmmm - sounds like the Clintons, huh?