Edited Date/Time:

It's a little bit early days still, as the UCI typically releases its schedules around the end of June or even in July, but the 2017 calendar has nevertheless been updated on their site. Sadly, it seems as though we can only look forward to 6 rounds of DH action next year, all the more baffling given how popular the sport is and how well the events are currently being run.
The schedule is set to take in some classic venues like MSA, Fort William, and Val di Sole, before concluding in the Southern Hemisphere for World Champs in Cairns. There is no US round, and Lenzerheide will somewhat perplexingly apparently NOT host a DH in 2017, even though they invested in a new track (built by Sir Peaty himself), hosted a DH event in 2015 and will host one this year. They are still slated to host an XCO in 2017, so maybe they can still decide to add DH as well, time will tell if there is a further update to the schedule over the coming months.
29-30 Apr UCI MTB WORLD CUP - DHI Lourdes FRA
20-21 May UCI MTB WORLD CUP - XCO Nove Mesto na Morave CZE
27-28 May UCI MTB WORLD CUP - XCO Albstadt GER
3-4 Jun UCI MTB WORLD CUP - DHI Fort William GBR
10-11 Jun UCI MTB WORLD CUP - DHI Leogang AUT
1-2 Jul UCI MTB WORLD CUP - XCO - DHI Vallnord AND
8-9 Jul UCI MTB WORLD CUP - XCO Lenzerheide SUI
5-6 Aug UCI MTB WORLD CUP - XCO - DHI Mont-Sainte-Anne CAN
26-27 Aug UCI MTB WORLD CUP - XCO - DHI Val Di Sole ITA
5-10 Sep UCI MTB WORLD CHAMPIONSHIPS - XCO/XCR/DHI Cairns AUS