Not really. While “Shabbat” is similar to the Hebrew word for seven, “Sheva”, it actually comes from the Semitic root S-B-T, which means “to halt”, “to rest” or “to be quiet”.
To elaborate:
Sábado, Domingo, Segunda-feira, Terça-feira, Quarta-feira, Quinta-feira, Sexta-feira
Saturday and Sunday, as mentioned, mirror Spanish.
Monday through Friday have the word feira in their names, which means market, such as a farmer’s market. This means the days are really “second-market”, through “sixth-market”
Brazilians often will clip off the “feira” part in conversation. “Na segunda eu tenho que voltar para trabalho.” (I have to go back to work on Monday)
Hmmm… I wonder if there’s a link!
We say Sixth Market, you say Sixth Day. Maybe the Portuguese term wandered from its origin a bit? Regardless, a Brazilian hearing “Sixth” will think “Friday”, as will, I suspect, a speaker of Hebrew.
Irish:
Monday = Dé Luain (from Latin dies lunae Moon Day)
Tuesday = Dé Máirt (from Latin dies martis Mars Day)
Wednesday = Dé Céadaoin = first fast day
Thursday = Déardaoin = day between the two fasts
Friday = Dé hAoine = fast day
Saturday = Dé Sathairn (from Latin dies saturni Saturn Day)
Sunday = Dé Domhnaigh (from Latin dies dominicus Lord’s Day)
From the above you might conclude that the Irish word for “day” is “Dé”. You would be wrong!
To add a layer to this explanation, the surface meaning of the words is:
Sunday/nichiyobi (日曜日＝太陽/←”taiyo”/”sun”) - SUN DAY
Monday/getsuyobi (月曜日＝月/←”tsuki”/“moon”) - MOON DAY
Tuesday/kayobi(火曜日＝火星/←”kasei”/”mars”) - FIRE DAY
Wednesday/suiyobi (水曜日＝水星/←”suisei”/“mercury”) - WATER DAY
Thursday/mokuyobi(木曜日＝木星/←”mokusei”/jupiter”) - WOOD DAY
Friday/kinyobi (金曜日＝金星/←”kinsei”/“venus”) - GOLD DAY
Saturday/doyobi (土曜日＝土星/←”dosei”/“saturn”) - EARTH DAY (earth the substance/element, not Earth the planet)
The connection with the names of Roman gods is therefore at one remove.