February 29th.
Applying this value to n I get a declination of 8.29 ° value very close
to 8.183 °.
At n equal to 284 is October 11
Applying this value to n I get a declination of 8.10 ° also it very
close to 8.183 °
Reflecting on the dates it gets is much more impressive but also more
realistic to think that the date is that of February 29 because it is
the day that is inserted into the leap year and is the only day that
exists once every 4 years, doing the Exceptions (see Gregorian
Calendar).
Even the resemblance between our Gregorian and Egyptian calendar makes
it much more likely that this day of the year is right.