It's the very first Grand Galloping Gala under the rule of princess Twilight Sparkle. The best part is, you've been invited

As you arrive at the party, you see Twilight herself, talking to her friend Applejack. It looks as if they haven't seen each other in a while. As Applejack leaves (probably to go back to her concession stand) you and Twilight make eye contact, and she holds it... She's staring at you...