Question: how to calculate days between two dates in plsql?
Answer: Full days between end of month and start of today, including the last day of the month: SELECT LAST_DAY (TRUNC(SysDate)) - TRUNC(SysDate) + 1 FROM dual.
Days between using exact time: SELECT SysDate - TO_DATE('2018-01-01','YYYY-MM-DD') FROM dual.