
On Jul 27, 2015, at 9:13 AM, Steven D'Aprano <steve@pearwood.info> wrote:
On Mon, Jul 27, 2015 at 10:54:02AM +0200, Lennart Regebro wrote:
On Mon, Jul 27, 2015 at 10:47 AM, Paul Moore <p.f.moore@gmail.com> wrote:
I'm confused by your position. If it's 7am on the clock behind me, right now, then how (under the model proposed by the PEP) do I find the datetime value where it will next be 7am on the clock?
PEP-431 does not propose to implement calendar operations, and hence does not address that question.
To me, Paul's example is a datetime operation: you start with a datetime (7am today), perform arithmetic on it by adding a period of time (one day), and get a datetime as the result (7am tomorrow).
To my naive mind, I would have thought of calendar operations to be things like:
- print a calendar; - add or remove an appointment; - send, accept or decline an invitation
What do you think calendar operations are, and how do they differ from datetime operations? And most importantly, how can we tell them apart?
The way I interpreted it is that "calendar operations" require knowledge of events like daylight savings time that require a more complete knowledge of the calendar, rather than just a naive notion of what a date and time are.