Handle datetime formatting and math with alfred

Download the latest release and double click to add to alfred.

• Specify a formatted time to switch to another format
• Use now, today, tomorrow, yesterday
• +/- <amount> <unit> to add or subtract time
  • units: microseconds(ms), seconds(s), minutes(min), hours(hr), days(dy), weeks(wk), months(mn), years(yr)
• next|prev <day of the week>
• start|end <unit>
  • units: day, week, month, year, decade, century
• to <timezone>
  • accepts local, utc, or a timezone
  • partial match timezone if it matches a single timezone (i.e. york matches America/New_York)
• Use a combination of the commands above
  • dt now + 2 weeks 2 days
  • dt next monday + 2 days
  • dt 2017-09-10 22:10:44 start week

• Handle time zone better
• Improve docs
• Allow users to define formats
• Add some tests to make sure things work