Reigning champions United are currently seventh in the Premier League, five points behind fourth-placed Liverpool.
United play five top-flight matches between now and mid-February, a sequence that starts with Sunday's trip to third-placed Chelsea and ends with a clash with current table-toppers Arsenal at Emirates Stadium.
And Vidic is aware United will have to find some consistency during this spell if David Moyes is to collect some silverware in his first season in charge at Old Trafford.
"We have to win regularly and in the next month we will know exactly where we are," Vidic said in Inside United magazine.
"By the end of January and start of February we will show what our position is and what our capability is in the Premier League.
"Then, of course, the Champions League starts up again. This is an important time for us and we all want to do well."
The 32-year-old insists Moyes should not be solely responsible for United's stuttering season, and that the players have to be held accountable as well.
"You have to always be together as a team," Vidic added. "That's important. If you have a bad result you have to concentrate on doing the right things - in training and with your behaviour, then in the matches.
"You try to lead by example first in the dressing room, then out on the pitch.
"We are lucky here because there are so many players who are experienced and mature people, they help the team try to achieve what we want to do."