Use Below script,
(ooxml, embedded labels, table is Sheet1);
(ooxml, embedded labels, table is Sheet2);
LOAD * Resident
DROP Table Table2;
The data is similarly like what is in the JDA. The reason I picked row 1 is below, by that time, the SKU is on sale, something like that...
ORIGINALLY THIS IS THE ACTUAL RAW DATA
** where 999999 means infinite...
** So to get the ranges and previous record must have an end date
** I sorted them and put end dates to those with 999999
** In my logic, if I found the first record is 999999 then I will leave it as is
** the red font determine the changes
Yes there is really overlapped on date ranges.