For example, our ferry arrives at RT on the 16th at 3:30 pm, so we are planning to be tested on the evening of the 14th. If it is two calendar days, we could test anytime on the 14th, but we're going to be on the safe side.
Unless others know something we don't know?
It's 2 days; has always been this way but worded differently (I don't know why they insist on this wording). For an arrival on the 16th, a test anytime on the 14th or 15th is fine. I have not heard of a single exception where someone was challenged about the specific time in all the months we've had testing requirements.