The dates in the main-ping are limited to a daily precision, but the creationDate (which is part of the common ping format) isn't. We should probably limit this one as well so that it has a daily precision.

I don't think we should limit it to daily precision, but use a precision of seconds, minutes or hours. Currently we submit the full hhmmss.sss, i think we don't need the fractional part at all. I think a precision of minutes is enough for all questions we might want to answer from this, which would be related to distributions of ping creation times. Benjamin, does that sounds ok from your data collection review perspective?

creationDate being the date/time this ping was created, or the profile creation date/time? I don't understand the tradeoffs here: who uses this piece of data? Do we use this to determine operational latency, for example? If so, having something smaller than days is probably useful. I don't think I have enough context about why this field exists to answer the question at hand.