Our calendars are off a bit.

In the year 1 we used the Julian Calendar, which was adopted in 45 BC. It has an accuracy of about 11 minutes per year, meaning after exactly 1 solar year, our clocks will be off by 11 minutes. It takes over 100 years for this to actually change the date. This was much better than the complete mess of a calendar system the Romans had before that, but nevertheless by the 15th Century it had drifted off by about 10 days, which was quite noticeable, and a real concern for the Church which was quite concerned about accurately calculating the dates for Easter. Since then, the error has grown to 13 days.

The Gregorian Calendar, proposed in 1582, has a much higher accuracy of 1 day in 3000 years or so. After 1 exact solar year, clocks will be off by about half a minute. (Although it actually gets quite complicated at this level of accuracy, because the length of a year is itself variable to some degree.) They didn't correct dates going back to year 1; rather they corrected them using the Council of Nicaea (323) as their point of reference. This is the calendar system we currently use, and from that accuracy you can see that there hasn't been enough time since the year 323 (or even year 1) for it to drift off by even a single day. But it's still off (by half a day or so), and given a few thousand years more we might even start to notice it. Corrections to the Gregorian Calendar have been proposed, but since the current error is still less than 1 day, our actual dates are not affected yet and nobody is treating the problem as urgent.

The English speaking world did not adopt the Gregorian Calendar until 1752 (it was an innovation of the Catholic Church, after all), so technically the years 1-1750 were off by 1 day in 100 years, and the years 1753-2019 were off by 1 day in 3000+ years. But 1752 was a bit of a doozy, and was off by 11 days in 1 year, because the switch from Julian to Gregorian meant that September 3 - 13 1752 did not exist. And 1751 was just confusing, because as part of the same calendar reform they decided to move the New Year from March 25 to January 1, so 1751 only had 282 days.