I'm surprised I haven't seen anyone post what seems like an obvious tip (that could almost be considered a cheat).
I'm an impatient sort, and get bored waiting around for the time to progress, so I close down the game, change my time forward by an hour or 2 (or 3), and then log back in. On double-speed (and hard difficulty), I just played a complete 89 hour game in about 4 real hours, solving all 16 puzzles. I birthed 20 babies, and only buried my original 5 folk. Kind of proud of the stats.
The only gotcha is you need to watch out for other time/date-sensitive apps, such as alarms in Outlook. And don't forget to reset the date and time when you are done!
SchneeBaer