[In those days, וַיְהִ֖י מִיָּמִ֑ים] And it was from days (Montanus); after some days (Syriac, Arabic, Pagnine, Piscator, Drusius), that is, so that it might be referred to that promise of the Gileadites, verse 2, which is to say, What they wished for themselves, that a little afterwards they pursued, etc. This exposition is favored by what follows (Piscator). With a certain amount of time elapsed (Vatablus). After a season of days (Jonathan). After those years (Junius and Tremellius), that is, in the last of those eighteen years, concerning which Judges 18:8 (Junius). But I do not recall days to be read in the place of years; in the place of a year of days, it is so well known that it need not be proven (Drusius). After days, that is, after a year. Thus in verse 40, from days to days, that is, from year to year, in a word, annually. They adduce these, among many other passages, to prove that יָמִים/days is often taken in the place of a year (Bochart’s Sacred Catalogue of Animals 2:4:10:505).
In process of time; Hebrew, after some days; or, after a year; days being oft put for a year, as hath been showed, after that year mentioned Judges 10:8. The Ammonites had vexed and oppressed them eighteen years, and now that the Israelites begin to make opposition, they commence a war against them. Or, some time after Jephthah had been banished, and after he had taken up arms, and given them some disturbance. Or, after the Israelites assembled together, as is said, Judges 10:18.
 Hebrew: וַיְהִ֖י מִיָּמִ֑ים וַיִּלָּחֲמ֥וּ בְנֵֽי־עַמּ֖וֹן עִם־יִשְׂרָאֵֽל׃
 Hebrew: מִיָּמִים.
 A woodenly literalistic rendering.
 Judges 11:40: “That the daughters of Israel went yearly (מִיָּמִ֣ים׀ יָמִ֗ימָה, from days to days) to lament the daughter of Jephthah the Gileadite four days in a year.”