אבן העזר ס״דEven HaEzer 64

Se’if 1א׳

הַנּוֹשֵׂא בְּתוּלָה צָרִיךְ לִשְׂמֹחַ עִמָּהּ שִׁבְעָה יָמִים, שֶׁלֹּא יַעֲשֶׂה מְלָאכָה, וְלֹא יִשָּׂא וְיִתֵּן בַּשּׁוּק, אֶלָּא אוֹכֵל וְשׁוֹתֶה וְשָׂמֵחַ עִמָּהּ, בֵּין אִם הוּא בָּחוּר בֵּין אִם הוּא אַלְמוֹן. וְחָתָן אָסוּר בַּעֲשִׂיַּת מְלָאכָה, וְאָסוּר לָצֵאת יְחִידִי בַּשּׁוּק (רַ"ן פֶּרֶק קַמָּא דִּכְתֻבּוֹת וּבְפִרְקֵי ר' אֱלִעֶזֶר):

One who marries a virgin should celebrate with her for seven days, during which time he should not do any work or buy and sell in the marketplace. Rather he should eat, drink, and be happy with her. This applies whether he we previously married or not. (Rema: A bridegroom is forbidden from doing work, and is forbidden from going to the marketplace alone [Ran, chapter kama d'ktiv and pirkei rav Eliezer]).

Se’if 2ב׳

הַנּוֹשֵׂא אֶת הַבְּעוּלָה צָרִיךְ לִשְׂמוֹחַ עִמָּהּ שְׁלשֶׁת יָמִים, בֵּין בָּחוּר בֵּין אַלְמוֹן. וְיֵשׁ אוֹמְרִים דְּבָחוּר שֶׁנָּשָׂא בְּעוּלָה צָרִיךְ לִשְׂמֹח עִמָּהּ שִׁבְעָה יָמִים. וְהָאִשָּׁה יְכוֹלָה לִמְחֹל עַל שִׂמְחָתָהּ (ר' יְרוּחָם נָתִיב כ"ב):

One who marries a previously married woman is required to celebrate with her for three days, whether he was previously married or not. There are some who say that a man who was never married previously who marries a previously married woman needs to celebrate with her for seven days. (Rema: And the woman is able to absolve the requirement for her joy, Rabeinu Yeruchum, 22).

Se’if 3ג׳

יֵשׁ אוֹמְרִים שֶׁאֵין נוֹשְׂאִין נָשִׁים לֹא בְּעֶרֶב שַׁבָּת וְלֹא בְּאֶחָד בַּשַּׁבָּת, גְּזֵרָה שֶׁמָּא יָבוֹא לִידֵי חִלּוּל שַׁבָּת בְּתִקּוּן הַסְעֻדָּה. וְיֵשׁ מַתִּירִין. וְכֵן פָּשַׁט הַמִּנְהָג לִשָּׂא נָשִׁים בְּעֶרֶב שַׁבָּת, וְהוּא שֶׁיִּטְרַח בִּסְעֻדַּת הַנִּשּׂוּאִין שְׁלשָׁה יָמִים קֹדֶם הַנִּשּׂוּאִין. וּמָקוֹם שֶׁאֵין בֵּית דִּין יוֹשְׁבִים בּוֹ אֶלָּא בְּשֵׁנִי וּבַחֲמִישִׁי בִּלְבַד, בְּתוּלָה נִשֵּׂאת בְּיוֹם רְבִיעִי, שֶׁאִם הָיְתָה לוֹ טַעֲנַת בְּתוּלִים יַשְׁכִּים לְבֵית דִּין. וּמִנְהַג חֲכָמִים שֶׁהַנּוֹשֵׂא אֶת הַבְּעוּלָה יִשָּׂאֶנָּה בַּחֲמִישִׁי, כְּדֵי שֶׁיִּהְיֶה שָׂמֵחַ עִמָּהּ שְׁלשָׁה יָמִים: חֲמִישִׁי בַּשַּׁבָּת וְעֶרֶב שַׁבָּת וְשַׁבָּת, וְיוֹצֵא לִמְלַאכְתּוֹ יוֹם רִאשׁוֹן. וְנָהֲגוּ שֶׁלֹּא לִשָּׂא נָשִׁים אֶלָּא בִּתְחִלַּת הַחֹדֶשׁ, בְּעוֹד שֶׁהַלְּבָנָה בְּמִלּוּאָהּ (הָרַ"ן סוֹף פֶּרֶק אַרְבַּע מִיתוֹת), וְעַיֵּן בְּיוֹרֶה דֵעָה סִימָן קע"ט:

There are some who forbid marrying on erev shabbat or Sunday. It is a stringency put in place to prevent a violation of shabbat during the wedding feast. There are those who are lenient regarding this practice. The minhag is to marry women on erev shabbat, as long as the bridegroom prepares for the wedding feast for three days before the wedding. A place that does not have a beit din except on Monday and Thursday, a virgin should marry on Wednesday so that if there is a claim on her [someone claims she is still married], they can go to the beit din. The minhag of the wise ones was that one who was marrying a previously married woman should marry her on Thursday so that he could celebrate with her for three days - Thursday, Friday, and Saturday, and return to work on Sunday. (Rema: There is a custom to only marry at the beginning of the month when the moon is getting fuller, Ran end of chapter arba mitot. See also yoreh deah siman 179)