I have a residence permit for Sweden that starts from 1/1/19. I have an Indian passport. I'm planning to travel from Chennai to Copenhagen by flight. The flight takes off at 3.30 AM from Chennai and reaches Copenhagen on 12.20 PM on 31st. Will there be any problems with the airline (Emirates) and transit layover at Dubai? I'm travelling abroad for the first time for study. I'm willing to spend 12 hours at Copenhagen midnight and 1/1/19. What will you suggest as an experienced traveler?
The airline will not let you board. The airline risks a fine of several thousand euros if you approach the passport desk before midnight, so your assurance that you will wait is probably not going to be very persuasive.
You should postpone your flight. Because you will enter the Schengen area in Copenhagen, you must arrive there after midnight, that is, actually on or after the first of January, local time.