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Dates arithmetic

Standard arithmetic operations are available on dates.

Convert a date to a day of week, so that:

  • 0 if sunday
  • 1 if monday
  • 2 if tuesday
  • 3 if wednesday
  • 4 if thursday
  • 5 if friday
  • 6 if saturday

The formula to implement is:


  • d is the date to compute the day of
  • 4d is the duration of four days
  • 1w is the duration of one week
  • mod is the modulo operator: it translates to % operator
  • ⌊ X ⌋ is the floor function

The euclidean division div will efficiently implement the floor and division operations.

archetype weekday

variable n : int = 0

entry weekday (d : date) {
n := (((d - 1970-01-01) + 4d) % 1w) div 1d


The following Completium CLI command deploys the contract on the Tezos network:

completium-cli deploy 5-weekday.arl

Call entry point

The following command calls the unique entry point:

completium-cli call 5-weekday --entry weekday --arg  '{ "d" : "2008-11-28" }'


Open '6-state_machine.arl' and click on "Next: State Machine" below.