Support for date shortcuts

[rohieb]

I use khal frequently on the command line, so I have aliased it to k in my shell. But navigating around the calendar or agenda with giving the full date is a bit cumbersome, I always have to type so much ;-) It would be of great help to have khal <date> as a shortcut to print the agenda for that date.

Then especially useful would be more date formats, e.g. khal 23rd would list the events at 23rd of the current month (maybe related to #169).

To be honest, my intended use of khal is heavily influenced by my usage of taskwarrior, which allows to filter tasks easily by giving a filter expression as the first parameter, and the "show events from this date" feels much like such a "filter". The taskwarrior manual has a long list of useful synonyms and date abbreviations, some of which could be useful for khal also.

[geier]

As khal is already a shortcut, by default to khal list, I believe adding any more shortcuts would make usage and implementation even more complicated. I would suggest instead alias k to khal list.

But adding some more shortcuts might be a good idea, but note, that we do support some of them the ones taskwarrior uses already, it's just not documented anywhere, currently supported:

• names of the day of the week, also in two letter abbreviated form
• today, tomorrow, yesterday
• now

[rohieb]

Aliasing k = khal list is indeed a solution. Then we have only the extended date syntax left. I would find especially useful:

• next month, or in general, mar, march, dec 2017, and 2017-12 (each resolving to the 1st of a month respectively), useful for khal calendar
• 23rd, 23.,12th, 12. etc. for the next day of month with that number

[geier]

I'm going to rename the issue to 'Support for date shortcuts' so it's clearer what's the unresolved part is about.

[lucc]

I have some ideas for other aliases, shortcuts, syntax date extensions:

• [this] {day,week,month,year} as a date range, (this day and day might be left out as we already have today)
• next {day,week,month,year} as date range
• until XXX where XXX is a datetime, this could by syntactic sugar for today XXX
• XXX +YZ where XXX can be any date range, +YZ is ment to be a relative time description with Y being a number (positive integral) and Z a letter from hdwmy, which should be interpreted as one of the units "hour", "day", "week", "month", "year". The result should be a date range starting at XXX and ending Y units Z later. (if XXX is left out it could default to now)

[geier]

date(time) [NX] + already works, where N is a number and X is one of d(ays), h(ours), m(inutes) or s(s econds) already works (with an optional space between mutlitple NX).

Example: khal new today 14:00 2h 30m meeting