As שָבָת  Shabbat, the Sabbath ends here in Israel, we say  שָׁבוּעַ   טוֹב ‏Shavua tov Good week Sunday,  יוֹם   רִאשׁוֹן Yom rishon in Hebrew,  Yom rishon, is the first day of the week.  Rishon רִאשׁוֹן means first and it is from the root רֹאשׁ Rosh, which means head.  The head of the week—Yom Rishon. יוֹם   רִאשׁוֹן Yom Rishon. יוֹם   רִאשׁוֹן  is the day of resurrection.  Yom Rishon, יוֹם   רִאשׁוֹן  the first day,  is the day of beginnings.  Look at the first word in the Bible....

כִּי הַתּוֹרָה נִתְּנָה עַל־יְדֵי מֺשֶׁה, וְהַחֶסֶד וְהָאֱמֶת בָּאוּ דֶּרֶךְ יֵשׁוּעַ הַמָּשִׁיחַ. For the Law was given through Moses; grace and truth were realized through Jesus Christ. Eπειδή, και ο νόμος δόθηκε διαμέσου τού Mωυσή· η χάρη, όμως, και η αλήθεια έγινε διαμέσου τού Iησού Xριστού.

אַתֶּם בַּקְּשׁוּ תְּחִלָּה אֶת מַלְכוּתוֹ וְאֶת צִדְקָתוֹ, וְכָל אֵלֶּה יִוָּסְפוּ לָכֶם. But seek first His kingdom and His righteousness, and all these things will be added to you. Aλλά, να ζητάτε πρώτα τη βασιλεία τού Θεού, και τη δικαιοσύνη του· και όλα αυτά θα σας προστεθούν.