NBC has tweaked its Tuesday scheduling plans for the fall, and it’s complicated — with Best Time Ever With Neil Patrick Harris moving around and The Voice switching back and forth between two-hour and one-hour episodes.

Best Time was originally slated to air in the 10 PM time period, following The Voice and new drama Heartbreaker until the new variety show ends its limited run in November when the slot’s regular, Chicago Fire, comes back.

First, NBC earlier this month announBest Time Ever Neil Patrick Harrisced that Heartbreaker was pushed to accommodate star Melissa George’s pregnancy, with the Chicago Fire spinoff Chicago Med taking its place in November. Now there is another wrinkle.

Best Time will debut the week before premiere week in its announced Tuesday 10 PM time slot, behind the season finale of America’s Got Talent.

For the following three weeks, until October 6, Best Time will air at 10 PM with a great lead-in, two-hour episodes of The Voice. Starting October 13, Chicago Fire will return to its 10 PM slot for a fourth season. Best Time will move to 8 PM, with The Voice temporarily shrinking to one hour (9-10 PM). That setup will be in place for four more weeks, until Best Time wraps its initial cycle. On November 10, The Voice again will expand to two hours, leading to the series premiere of Chicago Med, with Chicago Fire sitting the night out. Starting on November 17, NBC’s Tuesday lineup will assume its permanent fall makeup: The Voice, Chicago Med, Chicago Fire.

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Aside from the very complex Tuesday lineup, which will be full of moving pieces in September and October, the rest of the NBC fall rollout plans are straight forward. The bulk of the network’s series will launch during the premiere week of September 21, including new Thursday 8 PM anchor, Heroes Reborn

Along with other nets, NBC usually uses the Friday 8 PM hour the first couple of weeks of the season to give some new series extra sampling. That will be the case again this year, with Undateable launching its third season with an hourlong live premiere on October 9, joined by its new companion, new comedy People Are Talking, the following Friday. Also as usual, Grimm will premiere the Friday before Halloween.

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Here is a rundown of NBC’s fall premiere dates:

Thursday, Sept. 10
8:30-11:30 p.m. — SUNDAY NIGHT FOOTBALL (Pittsburgh at New England)

Tuesday, Sept. 15
10-11 p.m. — BEST TIME EVER WITH NEIL PATRICK HARRIS

Monday, Sept. 21
8-10 p.m. — THE VOICE
10-11 p.m. — BLINDSPOT

Wednesday, Sept. 23
8-9 p.m. — THE MYSTERIES OF LAURA
9-11 p.m. — LAW & ORDER: SVU

Thursday, Sept. 24
8-9 p.m. — HEROES REBORN
9-10 p.m. — THE BLACKLIST
10-11 p.m. — THE PLAYER

Wednesday, Sept. 30
10-11 p.m. — CHICAGO P.D.

Friday, Oct. 9
8-9 p.m. — UNDATEABLE

Tuesday, Oct. 13
10-11 p.m. — CHICAGO FIRE

Friday, Oct. 16
8:30-9 p.m. — PEOPLE ARE TALKING

Friday, Oct 30
9-10 p.m. — GRIMM

Tuesday, Nov. 10
10-11 p.m. — CHICAGO MED