MySQL - Move data between partitions aka re-partition

I have a mysql table whose partitions look as below p2015h1 - Contains data where date < 2015-07-01 (Has data from 2016-06-01. Hence only month worth of data) p2015h2 - Contains data where date < 2016-01-01 p2016h1 - Contains data where date < 2016-07-01 p2016h2 - Contains data where date < 2017-01-01 I'd like the new partitions to be quarterly based as below - p0 - Contains data where date < 2015-10-01 p1 - Contains data where date < 2016-01-01 p2 - Contains data where date < 2016-04-01 p3 - Contains data where date < 2016-07-01 I started by reorganizing the first partition & executed the below command. All went well. alter table table1 reorganize partition p2015half1 into (partition p0 values less than ('2015-10-01')); Now as the existing partition p2015h2 has data that includes data upto 2015-10-01, how could I move this part into the partition p0 ? I would need to do the same thing with the other partitions too as I continue building the new ones. I did try to remove partitioning on the table fully, but, the table is billions of rows in size & hence the operation will take days. Post this I will have to rebuild the partitions which will take days again. Hence, I decided to take the approach of splitting partitions. I'm stuck at this point in time. I'd fully appreciate any guidance here please.