Interval >1 may skip a week

[tim-phillips]

It appears that if dtstart is in the week before the first occurrence, then it will skip that occurrence, but if dtstart is in the same week then it will not. Any idea why this would be happening? Would be happy to open a PR.

import { RRule } from 'rrule'

const options = {
  freq: RRule.WEEKLY,
  interval: 2,
  count: 2,
  byweekday: [RRule.TU]
}

const rule1 = new RRule({
  ...options,
  dtstart: new Date(Date.UTC(2019, 10, 3))
})

const rule2 = new RRule({
  ...options,
  dtstart: new Date(Date.UTC(2019, 10, 4))
})

// rule1 and rule2 are across a week boundary
// rule1 results start a week later than rule2
console.log(rule1.all().map(toISOString))
console.log(rule2.all().map(toISOString))

function toISOString(d) {
  return d.toISOString()
}

https://codesandbox.io/s/rrule-interval-test-806pd

Expected output:

["2019-11-05T00:00:00.000Z", "2019-11-19T00:00:00.000Z"]
["2019-11-05T00:00:00.000Z", "2019-11-19T00:00:00.000Z"]

Actual output:

["2019-11-12T00:00:00.000Z", "2019-11-26T00:00:00.000Z"]
["2019-11-05T00:00:00.000Z", "2019-11-19T00:00:00.000Z"]

rrule@2.6.2 macOS 10.14.6 PDT

[FaberM]

I'm getting the same thing

[qweluke]

@FaberM @jakubroztocil any updates about this issue?