PoC Time+Date manipulation blocks

[tyeth]

The basic premise is all time related blocks will translate to a unix time in seconds (since 1/1/1970).

It should be assumed that all things are in User Timezone, unless stated otherwise (weather block values).
There is a settings cog to allow selecting timezone when appropriate, and also for strftime formatting options.

This is the block list (first two from original PoC by Justin [#34], but updated to work in seconds instead of minutes):

Combined with the Create Duration block (e.g. 2days) the user can do time/date arithmetic.

An example of the sunset calculator (2hrs before sunset) and a few block experiments:

And this is what's inside the format time as text block settings:

To recreate the washing machine monitor project in blocks, it would require accessing the updated_at property of a feed, so a new Get Feed Property block was proposed. See #43

[tyeth]

Don't worry so much about the files/code, more the concept and blocks. Run it locally and have a play around with something that would use time.