וַיְהִ֣י בִשְׁמוֹנִ֣ים שָׁנָ֣ה וְאַרְבַּ֣ע מֵא֣וֹת שָׁנָ֡ה לְצֵ֣את בְּנֵֽי־יִשְׂרָאֵ֣ל מֵאֶֽרֶץ־מִצְרַיִם֩ בַּשָּׁנָ֨ה הָרְבִיעִ֜ית בְּחֹ֣דֶשׁ זִ֗ו ה֚וּא הַחֹ֣דֶשׁ הַשֵּׁנִ֔י לִמְלֹ֥ךְ שְׁלֹמֹ֖ה עַל־יִשְׂרָאֵ֑ל וַיִּ֥בֶן הַבַּ֖יִת לַיהוָֽה׃
And it came to pass in the four hundred and eightieth year after the children of Israel were come out of the land of Egypt, in the fourth year of Solomon’s reign over Israel, in the month Ziv, which is the second month, that he began to build the house of the LORD.
Zohar
Both were “in the first day of the second month”, the two being one. That month, besides, is called Ziv (=brightness, splendour), in allusion to the brightness of the moon of that month in that year, by reason that then the worlds altogether found themselves in completion. AFTER THEY HAD COME OUT OF THE LAND OF EGYPT: this emphasizes the fact that Israel’s exodus from Egypt took place in the first month.