Debugging Challenge #5

Previously on Dr. Lambda's blog:

I have deviced a series of debugging challenges, some are easy, some are really hard, all come from real live systems. Good luck!

The Challenge

• 1 point if you can spot where the error is.
• +1 point if you can explain why.
• +2 points if you can explain how to fix it.

// @param date  string in the format YYYY-MM-DD
function isBeforeToday(date: string) {
  return new Date(date).getTime() 
      < Math.floor(Date.now() / 86400000) * 86400000;
}