"People are 5'10" tall not some silly number of cm."
But there are those who would say two meters is easier to visualize than six feet or so.
As for dates, the format usually comes from how people speak it. Americans are used to "March (the) 14th, 2018", so you have 03/14/2018. Many other countries go "14th of March, 2018" or similar (like Catorce de Marzo), so guess what floats your boat. I do find the YYYY-MM-DD format (with optional HHMMSS) useful for natural sorting (and I always use hyphens to avoid restricted characters). Since I grew up a Navy brat, I'm comfortable with 24-hour times, but I know that's not universal.
PS. For those unfamiliar, Z(ulu) time is military parlance for GMT/UTC while J(uliet) simply designates local time.