It seems like Sandra Bullock is a fan of anachronistic films these days. Two out of the last three films she's made have been supernatural stories dealing with the distortion of time. While 2006's The Lake House was a bittersweet romance featuring Bullock as a doctor falling for a man living two years in the future, Premonition finds her discovering her husband's death on a Wednesday, then jumping around to a different day in the same week every morning when she wakes up.
Maybe she wasn't born for a role in Quantum Leap, but for broad appeal, these movies are a huge improvement from her roles in Speed, Miss Congeniality and their sequels.
Midway through the film, Bullock finally scrawls a one-week calendar onto her daughter's art pad, jotting down events occurring on each day, trying to make sense of her tumble through time. Unless you have a mind like a steel trap (unlike me), you too may find it easier to take notes as the film goes on. The basic plot is easy enough to follow, but either intentionally or accidentally (meaning the director screwed up), some of the events in the timeline don't make any sense.
Regardless of whether you catch any errors or completely follow or believe it could really happen, this is the best time-travel thriller since 2000's Frequency. And if you accept it for what it is, it's quite a bit of fun.