Manipulation of date & time

[m-mohr]

Adds a new process date_shift, see #247.

Took the simplest path for now...

[m-mohr]

I've pushed a new commit which improve date_shift and adds implementation details, incl. list of supporting libraries.
Leap seconds are better described, more examples given and it should be better structured in general.
The supporting libraries have been checked to comply to this specification, except for dateutil. Could you confirm that, @soxofaan ?

From my side the only open points are the parameter names then?

[soxofaan]

dateutil. Could you confirm that, @soxofaan ?

yes:

>>> from datetime import datetime
>>> from dateutil.relativedelta import relativedelta
>>> datetime(2021, 1, 31) + relativedelta(months=1)
datetime.datetime(2021, 2, 28, 0, 0)
>>> datetime(2020, 1, 31) + relativedelta(months=1)
datetime.datetime(2020, 2, 29, 0, 0)
>>> datetime(2020,2, 29) + relativedelta(years=1)
datetime.datetime(2021, 2, 28, 0, 0)

[soxofaan]

From my side the only open points are the parameter names then?

yes I would prefer something more self-descriptive than date_shift(data, value, unit). Especially the data looks like a typo to me

[m-mohr]

yes:

Great, thanks. Could you also quickly verify that the following works?

{ "description": "The process skips over the leap second `2016-12-31T23:59:60Z`.", "arguments": { "data": "2016-12-31T23:59:59Z", "value": 1, "unit": "second" }, "returns": "2017-01-01T00:00:00Z" },

[soxofaan]

indeed, leap seconds are ignored (or even considered invalid)

>>> datetime(2016, 12, 31, 23,59, 59) + relativedelta(seconds=1)
datetime.datetime(2017, 1, 1, 0, 0)
>>> dateutil.parser.parse("2016-12-31T23:59:60Z")
...
ValueError: second must be in 0..59