Is there proof that we never skipped a day of the week? [duplicate]

Question

Bereshit begins with the first 6 days and the Shabbat. The assumption is then that after that day, Mankind kept track of the day of the week all by themselves until today.

Are we sure that no one made a mistake between creation and today? Skipped a day? Are we sure that today is Sunday and not really Monday?

There have been generations that did not care about Shabbat (until the Hebrews I guess), and maybe they didn't care about weekdays? Maybe Noah on the Ark was not always able to keep track by himself? Or just in general - isn't a mistake possible?

Answer 1

The dating of Shabbat that Jews rely on goes back to יציאת מצרים and Matan Torah, not to Creation. When the Torah was given, the day was given over also. In fact, the purpose of Shabbat is also to remember יציאת מצרים (see the 4th Commandment in Devarim), so that can be considered the date that is being remembered. As long as a community of Jews was keeping Shabbat, the day would not have been messed up.

Note that according to Rabbi Menachem Kasher's unusual position on the Dateline, the day for Shabbat just follows the community (cited here). This would probably mean it doesn't matter if everyone messed up and moved the day, that would just be the new day for shabbat.

Answer 2

indeed it could be possible, but we have to consider the fact that at a regular pattern of 28 years the vernal equinox (traditionally the position that the sun was created in) comes out on the same day which is a Wednesday and we say Birchat Hachamah, if there had been a miscount perhaps it could've been observed this way (ie. if the pattern was maintained exactly or not) however as my knowledge of astronomy is almost none exhistant I have know way of knowing how accurately this occurance could've been measured without use of satellites etc.