Not being a jerk does make a big difference.

Ru-Ba-Ru (2008) is an example of a surprisingly popular subgenre in which a bad boyfriend or husband is given a magical second chance to live key points of their relationship over again, like A Christmas Carol but with more kissing. 

Nikhil (Randeep Hooda) and Tara (Shahana Goswami) live together in a surprisingly spacious apartment in Bangkok.  They're happy, mostly, but the cracks are starting to show.  Tara wants to get married, or at least wants to introduce Nikhil to her parents or meet his parents - some sign that they've got an actual future together.  

On the other hand, Nikhil has a specific future in mind, and he's entirely focused on making it happen.  He's preparing for a big presentation at work, which means that he's far too busy to go to India to meet her parents, or remember their anniversary, or buy her flowers when she has a play opening that night, or speak to her politely for more than two sentences in a row . . .  After a brief conversation with a wise and mysterious cab driver (Kulbhushan Kharbanda) Nikhil tries to make up with Tara, but he's still prickly and focused on his own work, and once Tara realizes that he's invited his clients to their romantic post-show dinner, she storms off, gets into a cab (driven by the same mysterious cab driver) and dies when another car hits the cab.

Nikhil is devastated.  He goes home and collapses, but in the morning he wakes up with Tara next to him.  She's fine, and Nikhil quickly realizes that he has a literal second chance, and has a whole day to live over again.  But while things can change, events seem to fall into the same pattern; Tara doesn't burn her arm while making Nikhil a coffee, but she does burn her arm while ironing his shirt.  The mysterious cab driver advises him to just spend time with Tara and make her happy, so he tries.  He takes her to meet his mother (Rati Agnihotri), mending that broken relationship in the process.  He focuses on Tara's needs rather than his presentation.  He arrives on time to the play and actually pays attention.  And at the end of the evening, he gets in the cab.

Ru-Ba-Ru is tightly focused on the central story, without any of the branching subplots Bollywood movies like to indulge in.  However, there's not much top that main plot; the movie is less than two hours long, and it still feels padded in places.  

The real problem, though, is Nikhil.  He's self-centered, controlling, and tries to present every one of his mistakes as Tara's fault.  he's a walking collection of red flags, and while he does improve when given his second chance, he's still loving and attentive in a sort of controlling way, which makes it really hard to root for him.  On the other hand, he does make the right choice at the end, and he does so without expecting a happy ending.

What I like about the movie is that there's no attempt at an explanation for the repeated day.  The closest we get is the cab driver explaining that his job is to help those who have lost their way find their destination.  Is the cab driver actually Death?  Was Nikhil such a bad boyfriend that it broke the space time continuum?  It is a mystery.