Learning jq through a timesheet app

• Running the timesheet app
• jq step by step
  • Generate some JSON files from YAML files
  • How to pretty-print the data (files in YAML format) and the generated JSON files?
  • See the timesheet for the week 07 in 2021
  • In which weekdays do we have an entry for the week 2021-07?
  • Do we have an entry for …​
  • How to force jq returns a valid exit code to shell?
  • Can we see the entries for Monday and for Wednesday?
  • How can I see the start/end times for Monday?
  • But we can have more than one start/end time for the same day. Is this right?
  • How to convert a string that represents a time in order to use it in time calculations?
  • Can we pass a "time string" to jq?
  • Something gets wrong …​
  • Parsing a date/time (converting it from a string)
  • Converting a date/time to a string
  • How to calculate a duration (the time between start/end times)?
  • How to create a jq library?
  • How to use a jq library?
  • How to convert "Year-WeekNumber.DayOfWeek" to date?
• References