That date will be July 5 and ends a 23-year-long career with Newshub, formerly TV3.
Last week, Warner Bros. Discovery confirmed Newhub's operations would be shut down and 250 people would lose their jobs.
McRoberts' announcement on Friday comes just days after multimedia company Stuff and WBD announced that Stuff would take over the 6pm bulletin on the TV channel Three. It is not known how many Newshub staff will be retained.
In a statement, McRoberts said: "Ka mutu taku haerenga hei kaikawe kōrero, he haerenga i hīkoi tahi ai tatou - my journey as a news presenter is coming to an end, a journey we hav
e walked together. Newshub's last six o'clock bulletin... will be my last presenting the news.
"When I started in this industry as a teenager 40 years ago I could not have imagined in my wildest dreams what an incredible adventure it would be.
"I feel so privileged to have had the opportunities I have had, none more so than in the past 23 years at Newshub, 3 News and 60 Minutes.
"This journey has taken me to some of the biggest stories around the world and to every corner of Aotearoa."
In the statement, McRoberts thanked the "wonderfully talented" people he had worked alongside, those who had trusted him with their stories, and the audience.
"This is my 20th year presenting the six o'clock news and it has been the greatest honour representing the very best in the business.
"For the last eight years I've shared that honour with my co-host Sam Hayes and will continue to do so for the next 11 weeks. I couldn't think of a better way to end my presenting career."
McRoberts said he would miss the whanaungatanga (closeness) of the Newshub team - but it was the right time to step away and pursue other opportunities.
"E kore e mutu taku mihi nui ki te aroha me te tautoko a te katoa i whai wāhi. I am forever grateful for the love and support of everyone involved."
Newshub's interim senior director of news Richard Sutherland said McRoberts was a man of immense mana.
"He has told stories of great consequence with passion, humanity and dignity.
"He is a true leader, who I have been proud to work alongside. He kotuku rerenga tahi. A white heron flies once."
In August 2022, McRoberts appeared on re_covering, a podcast produced by RNZ, where he spoke of his time reporting in Gaza.
McRoberts had lobbied his 3 News bosses to get him to the frontline of the war. For weeks, he found himself reporting from the centre of one of the deadliest conflicts between Israel and Palestine in decades.