Extract date type data in NiFi 1.9.2

The data is convert other type automatically?How can i get raw data?
Source Table:


DF:

Result:

solution:

updated:
/STARTTIME ${field.value:toNumber():toDate(“yyyy/MM/dd HH:mm:ss”, “GMT+8”):format(“yyyy/MM/dd HH:mm:ss”, “GMT+8”)}