There might be a delay before it gets sent, so it's better to record the time the event occurred at.
It would have been simpler to just add it to the data hash, but I felt it was an important detail for an event and should be at the top level along with event name.
In the case of order cycle opening, this is the same as opened_at. I've included this in the payload for clarity too.
It was probably better to be explicit at each test, but this one is always repeated and approaches the line length, so I wanted to just define it once at the top.
