Jerusalem Talmud Bava Metzia 2.6

משנה: עַד אֵימָתַי חַיָיב לְהַכְרִיז. עַד כְּדֵי שֶׁיֵּדְעוּ שְׁכֵינָיו דִּבְרֵי רִבִּי מֵאִיר. רִבִּי יְהוּדָה אוֹמֵר שְׁלֹשָׁה רְגָלִים וְאַחַר הָרֶגֶל הָאַחֲרוֹן שִׁבְעַת יָמִים כְּדֵי שֶׁיֵּלֵךְ לְבֵיתוֹ שְׁלֹשָׁה וְיַחֲזוֹר שְׁלֹשָׁה וְיַכְרִיז יוֹם אֶחָד.

MISHNAH: How long does one have to make it public. Until his neighbors know, the words of Rebbi Meïr. Rebbi Jehudah says, three holidays, and after the last holiday seven days so that one goes home during three days, comes back during three days, and makes it public for one day.

הלכה: עַד מָתַי חַיָיב לְהַכְרִיז כול׳. תַּנֵּי. בָּרִאשׁוֹנָה הָיוּ מַכְרִיזִין שְׁלֹשָׁה רְגָלִים וְאַחַר רֶגֶל הָאַחֲרוֹן שִׁבְעַת יָמִים כְּדֵי שֶׁיֵּלֵךְ שְׁלֹשָׁה וְיַחֲזוֹר שְׁלֹשָׁה וְיַכְרִיז יוֹם אֶחָד. מִשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ הִתְקִינוּ שֶׁיְּהוּ מַכְרִיזִין שְׁלֹשָׁה יָמִים. מִן הַסַּכָּנָה וְאֵילַךְ הִתְקִינוּ שֶׁיְּהֵא מוֹדִיעַ לִקְרוֹבָיו וְלִשְׁכֵינָיו וְדַייוֹ.

HALAKHAH: “How long does one have to make it public,” etc. It was stated: In earlier times one made it public during three holidays, and after the last holiday seven days so that one goes home during three days, comes back during three days, and makes it public during one day. After the destruction of the Temple they instituted that one has to make it public during three days. Starting from the danger they instituted that one has to inform his relatives and neighbors; this is sufficient.