The Christmas party clearly happens in the evening; there are even some exterior shots of the parking lot in darkness. However, most of Michael's talking-head interviews are done in the daylight (visibly seen through his office window). As the conversations relate to party events, i.e. Michael attempting "reverse psychology" during the Yankee Swap, it is implausible that the interviews were done pre-party and, therefore, the sky should already be dark.
Michael's bonus is $3000. He calls it 3000g's, which is $3 million.
For the gift exchange, Oscar is giving Creed an Irish key chain. In a talking head, he holds the gift up and refers to it as a Shamrock key chain; in fact, it has a four-leaf clover on it. Shamrocks have only three leaves.