仕様変更に対応した。また、実行するページの範囲を差し戻した。

G+.FormatDate.user.js

// ==UserScript==
// @id             G+ FormatDate
// @name           G+ FormatDate
// @namespace      https://raw.github.com/gist/1115074/G+.FormatDate.user.js
// @author         suVene
// @version        0.2.1.20110805182249
// @description    formate date for post date
// @include        https://plus.google.com/*
// @run-at         document-end
// @priority       0
// @compatibility  Firefox 5.0(Scriptish 0.1.3), Chrome 13.0.782.107, Safari 5.1(NinjaKit 0.8) on Windows 7 Enterprise 32bit
// @charset        UTF-8
// @note           Opera 11.50だと何故かGoogle+上でUser Scriptを実行することができない?
// ==/UserScript==

/* jslint browser: true, maxerr: 50, maxlen: 80, indent: 4 */
// Edition 2011-08-03

(function (doc) {
    'use strict';

    var postLinkList = doc.querySelectorAll(
            'span > [title]:not([role]):not([id])'
        ),
        postLinkListLen,
        contentPane,
        dayWeek,
        normalizeRegExp,
        dayWeekRegExp,
        timeReplace;

    if (!postLinkList) {
        return;
    }

    postLinkListLen = postLinkList.length;
    contentPane = doc.getElementById('contentPane');
    dayWeek = ['日', '月', '火', '水', '木', '金', '土'];
    normalizeRegExp = /（|）|編集:/g;
    dayWeekRegExp = /\d(?=\s)/g;
    timeReplace = function timeReplace(postLink) {
        var postTimeList = postLink.title.replace(
                normalizeRegExp,
                ''
            ).split('\n '),
            postTimeListlen = postTimeList.length,
            postTime;

        if (postTimeListlen > 1) {
            while (postTimeListlen) {
                postTime = postTimeList[postTimeListlen -= 1];

                postTimeList[postTimeListlen] = postTime.replace(
                    dayWeekRegExp,
                    '$&(' + dayWeek[(new Date(postTime)).getDay()] + ')'
                );
            }

            postLink.textContent =
                postTimeList[0] + ' (編集: ' + postTimeList[1] + ')';
        } else {
            postTime = String(postTimeList);

            postLink.textContent = postTime.replace(
                dayWeekRegExp,
                '$&(' + dayWeek[(new Date(postTime)).getDay()] + ')'
            );
        }
    };

    while (postLinkListLen) {
        timeReplace(postLinkList[postLinkListLen -= 1]);
    }

    if (contentPane) {
        contentPane.addEventListener('DOMNodeInserted', function (event) {
            var target = event.target;

            if (
                target &&
                    target.title &&
                    !target.id &&
                    target.parentNode.tagName === 'SPAN'
            ) {
                timeReplace(target);
            }
        }, false);
    }
}(document));