The old Mactime countdown had issues with accuracy when setting dates far into the future, sometimes being off by hours or even days. To fix this, we switched to a day-based countdown system instead of using months and days. Months can have different numbers of days, which made the old system inaccurate. Now, we count the total number of days and use an average of 30 days per month to convert it into months. This makes it easier to understand without causing errors. It's a simple but clever solution.