The dates and times surrounding the life of Jesus are not very far wrong, but there is some uncertainty.
There are three main calendars involved:
Because a year is not an exact whole number of days, man-made calendars and clocks do not keep in step with the natural times and seasons unless adjustments are made now and again.
In our days, scientists keep our calanders and clocks in step very accurately, adjusting our clocks by a mere second when necessary.
The time governers also use the “leap year” (an extra day in February) to keep our calendar from ever getting more than a day out of kilter.
However this attention to the accuracy of calendars was not always maintained.
At some periods down through the centuries, the calendar got so out of alignment with the seasons that things like seedtime and harvest were seriously affected.
Even when adjustments were made, they were sometimes gross, confused, and parochial.
The lack of uniformity in calendars used in the past, and in the adjustments made to them, creates difficulties in establishing dates more accurately than a close approximation.