I'm using the more extensions for Date and found something
interesting:
today = Date.parse('3/5/2010');
today.set("date") = 1;
also tried:
today.set("day") = 1;
The docs suggest you are able to reset the date:
All of the native date methods work with set. These are: "Date",
"FullYear", "Hours", "Milliseconds", "Minutes", "Month", "Seconds",
"Time", "UTCDate", "UTCFullYear", "UTCHours", "UTCMilliseconds",
"UTCMinutes", "UTCMonth", "UTCSeconds"
