Day off

[daniele-xp]

/t ferie 14 could track the 14 under project "Assenza" with tag "Ferie" (as standard procedure wants)

[ilbonte]

I can work on this in the next "pomodori di studio" :)

TODO:

• [x] acceptance test
• [x] track with label
• [x] don't track weekend days as day off (nice to have)
• [x] track multiple days e.g. /ferie 10-12 (nice to have)

[daniele-xp]

@ilbonte if you want we can do it together in pair ;)

[ilbonte]

I'm working on the last two missing features: https://github.com/ilbonte/trackerbot/commit/35583296559ccea59f8e64641167b926b2282052

The feature is available but the code should be refactored