Shabbat comes from the Hebrew word for sit/rest. Shabbat is the day of rest.
The only day of the week which has a name in Judaism is the Shabbat, which is named in the Torah (Exodus ch.31). Other days are simply called so-and-so-many-days-after-Shabbat.
In Hebrew, the days of the week are named "First Day", "Second Day" . . . . "Sixth Day", "Shabbat"."First Day" corresponds to the world-wide Sunday, and "Shabbat" corresponds to the world-wide Saturday.
They prepare their children for Shabbat and light the Shabbat candles.
"Shabbat Shalom!"
They're called Shabbat candles (Neirot Shabbat in Hebrew).
Shabbat Shabbatot
After Shabbat, there is the Havdalah service.
Shabbat shalom is a Jewish greeting which we say during the day of Shabbat. See also:More about the Jewish Shabbat
Shabbat Shalom (שבת שלום).Note: This means 'A peaceful shabbat'. The phrase "happy shabbat" is not a phrase that is traditionally used.
There is no issue with swimming during Shabbat, however, you wouldn't be able to shower after swimming until Shabbat ends. (Assuming you wish to be Shabbat observant.)
Judaism.See also:More about Shabbat
There is no reason to not allow Shabbat.