Use us precision to represent timestamps.

[paurkedal]

Using %.f means whole seconds only which makes history searches imprecise. This uses 6 digits to match what Slack supports.

Counting digits, it seems a float should suffice to provide the given precision, though I still worry about rounding errors converting between base 2 and base 10. Would it be better to use precise time stamps, e.g. using Ptime.t? I know at least two indicators that Slack deals with microsecond-precise timestamps:

• The channel history method has an inclusive option, which makes no sense if timestamps have rounding errors.
• When one receives edit and delete events though the RTM, they suggest matching past messages using channel and time stamp only. That is, the time stamp identifies a message in a channel, so they probably ensure that there is at least one microsecond between messages.

I can send a new PR changing time stamps to Ptime.t if you wish.

[Leonidas-from-XIV]

Thanks! I agree that representing that as a Ptime.t would most likely be better, so if you want to submit a PR I'd be definitely willing to merge it.