CHICAGO -- Forget what time the game starts. Day game, as originally scheduled, or a rare Friday night game at Wrigley Field, following a switch made to get the Cubs a little more rest upon their return from Pittsburgh.
Whenever the first pitch is thrown, here's what time it will be on Friday, Saturday and Sunday: winning time.
It's time for the Cubs to gain some more steam as they try to become the second team in 15 years to win their division the year after winning the World Series. And there's still plenty of time left for the Brewers to show they are for real as contenders, even if they are a little ahead of a rebuild schedule that should have them in plenty of big series in upcoming seasons.
They sure were intriguing when they were in the process of extending their unexpected lead in the National League Central to 5 1/2 games at the All-Star break. But the Crew has gone 20-27 since July 15, and it seems like light years since Eric Thames served notice with his big series at Wrigley Field in April.
Things have a way of changing fast in September, the month Orioles manager Buck Showalter says will reveal the lasting truth for contenders. Just three weeks will be left in the season when this three-game series is over, so closing time is coming fast.
Here are three key questions hanging over the teams. First, the Brewers:
1. Where did the firepower go?
After leading the NL with 138 home runs and scoring almost five runs per game in the first half, the Brewers are averaging 3.6 runs in the second half. They're going to have a really hard time catching the Cubs or outlasting the Rockies and Cardinals for a Wild Card spot if they don't start making loud noises with their bats.
There's a lot of focus on Thames, who has been defused by pitchers and advanced scouts since his fast start. He homered once every 11.9 at-bats in the first half, but once every 28.6 at-bats in the second half. Ryan Braun has just four home runs in the second half. A good weekend for those two guys would go a long way.
2. Is this a blip or a collapse by the bullpen?
After promoting lefty Josh Hader and trading for Anthony Swarzak, Milwaukee's bullpen was a godsend for manager Craig Counsell, who didn't need his starting pitchers to go six innings every night. But the bullpen has begun to show the wear and tear of the long season, sliding into the middle of the pack in bullpen ERA for the second half (4.21).
Nothing wrong with All-Star closer Corey Knebel, however. He has converted his past 16 save chances and 32 of 37 overall.

3. Can a chip on their shoulders be converted into wins?
It's natural for the Brewers to be sick of the Cubs. They've gone 26-43 against them over the past four seasons and would love to reverse that trend.
But they haven't been happy about three scheduling decisions by Cubs management: an early call for a rainout on May 20 when they felt the game could have been played; that game being rescheduled as a day game on July 6 in Chicago after they had a home game the night before; and the Cubs moving the time of this series opener to have a regular-season Friday night game at Wrigley for the first time and to allow their club a decent night's sleep.
As for the Cubs:
1. Can they rely on their hitters to carry them?
It took a long time for the Cubs to get the lineup to click, but they've been pounding the ball since the All-Star break, posting a Major League-high 5.9 runs per game, along with 81 home runs, most in the NL.
They've done it with a constantly changing lineup, with big contributions from reigning NL MVP Award winner Kris Bryant and Anthony Rizzo, who has been the most valuable Cub this season, offsetting the struggles of Kyle Schwarber and a series of injuries. Javier Baez has been a force offensively and as Addison Russell's replacement at shortstop.

2. Can they consistently get leads to Wade Davis?
Davis is baseball's most reliable closer, nailing down all 29 save situations this season. Nevertheless, the bullpen is the biggest question for the Cubs, as was the case heading into the postseason the past two years.
Manager Joe Maddon loved the job his relievers did early in the season, but it has endured too many meltdowns of late. Right-hander C.J. Edwards hasn't been nearly as effective as he was this time last year. He could be a key to the turnaround, and Maddon will work the matchups to try to put his guys in the right spot.
3. How's Jacob Arrieta's hamstring?
The Cubs have dealt with a series of injuries in the second half, including the loss of Russell and catcher Willson Contreras. But outside of the strained lat that sent Jonathan Lester to the disabled list, nothing has been more alarming than Arrieta's early exit from a start Monday in Pittsburgh.

The trio of Arrieta, Lester and Kyle Hendricks have given the Cubs an edge in five of the six postseason series they've played the past two years (the exception being the 2015 NL Championship Series against the Mets). Arrieta will miss his scheduled start Saturday, but he hopes not to miss more than one more. He has been the Cubs' best starter, going 7-2 with a 1.69 ERA during an 11-start stretch prior to straining his hamstring. The Cubs need Arrieta to maintain that effectiveness when he returns.