I provide technical support for software users. These users export data from
the software with multiple columns and multiple rows. One column for End
Date is formatted as Custom format Type: m/d/yyy" "h\:mm\:ss AM/PM.

These files are often very large, sometimes over 55,000 rows. The problem
happens when there are multiple rows in a row without data. It seems as if
the formatting is lost.

For example, the first ten rows have data recorded (date and time) and there
are then 500 rows with blank data and then the next ten rows (rows 511
through 521) have data. These cells don't seem to retain the proper
formatting. They show the date but not the time.

I'm sorry if I can't explain this well. Has anyone ever seen anything like
this? I'm not even sure how to search for similar posts on this issue.

Any help would be appreciated.