MYSQL SELECT statement failing within an UPDATE, within a LOOP - mysql

Question

I am writing a stored procedure to update a company calendar. The calendar data is stored within a MYSQL table. The stored procedure is an insert function which should force all calendar events between two dates to be shifted to the next available business day. Type 1 denotes a day on the calendar. Type 2 denotes an event on the calendar.
The calendar recognizes a business day through the Moves column. A day with Moves(more than 0) is a business day on the calendar.
When I run this query by itself, it returns the expected information:
SELECT `Date`, Moves FROM tblschedules WHERE Type = 1;
It gives me the number of Moves for each day. However, when I try and update the table, the update does nothing, because the Moves column returns as NULL. Here is the query for the update:
SET SQL_SAFE_UPDATES = 0;
UPDATE tblschedules tb1
INNER JOIN (SELECT `Date`, Moves FROM tblschedules WHERE Type = 1) tb2
ON tb2.Date = tb1.Date
SET tb1.Date = tb1.Date + Interval 1 Day
WHERE tb1.Type = 2 AND tb1.Date >= ddate AND tb1.Date < opendate AND tb2.Moves = 0;
So, to debug, I began putting select statements within my stored procedure, and found that the initial query is not returning the Moves column, but instead returns null values as Moves. So that tb2 is returning every Date properly, but is not retrieving the Moves values properly.
Here is the larger block of code. The intloop, ddate and opendate are all functioning properly.
looplabel: Loop
/* Select Statements for Debug Purposes*/
SELECT opendate;
SELECT ddate;
SELECT intloop;
SELECT `Date`, Moves FROM tblschedules WHERE Type = 1;
SELECT * FROM tblschedules tb1
LEFT JOIN (SELECT `Date`, Moves FROM tblschedules WHERE Type = 1) tb2
ON tb2.Date = tb1.Date
WHERE tb1.Type = 2 AND tb1.Date >= ddate AND tb1.Date < opendate;
/* End of Select Statements for Debug Purposes*/
IF IFNULL(intloop,0) = 0 THEN
LEAVE looplabel;
END IF;
SET SQL_SAFE_UPDATES = 0;
UPDATE tblschedules tb1
INNER JOIN (SELECT `Date`, Moves FROM tblschedules WHERE Type = 1) tb2
ON tb2.Date = tb1.Date
SET tb1.Date = tb1.Date + Interval 1 Day
WHERE tb1.Type = 2 AND tb1.Date >= ddate AND tb1.Date < opendate AND tb2.Moves = 0;
SET intloop = intloop - 1;
END LOOP;
I am not sure why the table returns the Moves properly outside of the stored procedure, but not inside of the stored procedure. I am wondering if it might have something to do with uncommitted changes/table locking. Its probably something basic and stupid I am missing. Thank you for your time.