When is hajj 2017? As per the estimates,
Hajj 2018 dates: Hajj 2018 will fall between 19 August, 2018 Sunday and 24 August, 2018 Friday, insha-Allaah.
Hajj 2019 dates: Hajj 2019 will fall between 9 August, 201 Friday and 14 August, 2019 Wednesday.
Hajj 2020 dates: Hajj 2020 will fall between 28 July, 2020 Tuesday and 02 August, 2020 Sunday.
There is a small probability of one day error.

The Hajj takes place from the 8th to the 12th of Zul-Hijjah which is the last month of the Islamic lunar / Hijri calendar.

The Islamic or Hijri Calendar is a lunar calendar based on moon sightings. The actual advent of each month depends upon the physical sighting of the new moon. The corresponding Gregorian dates are estimates based upon astronomical calculations, endorsed by the Fiqh Council of North America. The Gregorian dates for Hajj change from year to year.

The Islamic day begins at sunset.