HTTP latency buckets units

[Sebruck]

Hi,

in https://github.com/census-instrumentation/opencensus-specs/blob/master/stats/HTTP.md it is described that the buckets for latency should be ms.

Latency in ms: 0, 1, 2, 3, 4, 5, 6, 8, 10, 13, 16, 20, 25, 30, 40, 50, 65, 80, 100, 130, 160, 200, 250, 300, 400, 500, 650, 800, 1000, 2000, 5000, 10000, 20000, 50000, 100000

Prometheus recommends seconds as base unit https://prometheus.io/docs/practices/naming/#base-units

Is there a reason why we diverged from that? Are there any advantages by picking the one over the other?