On a bright day
By extension: suddenly on one of the days. At some point in time.
(The Modern Hebrew)
Translation
Expression (Hebrew)
בְּיוֹם בָּהִיר אֶחָד
Definition (Hebrew)
בְּהַשְׁאָלָה: פִּתְאֹם בְּאַחַד הַיָּמִים. בְּזְמַן כָּל שֶׁהוּא.
(הָעִבְרִית הַחֲדָשָׁה)