Iterate over dates range (the scala way)

Question

Given a start and an end date I would like to iterate on it by day using a foreach, map or similar function. Something like

(DateTime.now to DateTime.now + 5.day         


        

Answer 1

This answer fixes the issue of mrsrinivas answer, that .get(ChronoUnits.DAYS) returns only the days part of the duration, and not the total number of days.

Necessary import and initialization

import java.time.temporal.ChronoUnit
import java.time.{LocalDate, Period}

Note how above answer would lead to wrong result (total number of days is 117)

scala> Period.between(start, end)
res6: java.time.Period = P3M26D

scala> Period.between(start, end).get(ChronoUnit.DAYS)
res7: Long = 26

Iterate over specific dates between start and end

val start = LocalDate.of(2018, 1, 5)
val end   = LocalDate.of(2018, 5, 1)

// Create List of `LocalDate` for the period between start and end date

val dates: IndexedSeq[LocalDate] = (0L to (end.toEpochDay - start.toEpochDay))
  .map(days => start.plusDays(days))

dates.foreach(println)