public Date parse(String text,
Parses text from a string to produce a Date.
The method attempts to parse text starting at the index given by pos. If parsing succeeds, then the index of pos is updated to the index after the last character used (parsing does not necessarily use all characters up to the end of the string), and the parsed date is returned. The updated pos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of pos is not changed, the error index of pos is set to the index of the character where the error occurred, and null is returned.
CALL FUNCTION 'DATE_CHECK_PLAUSIBILITY'
date = v_date
plausibility_check_failed = 1
OTHERS = 2.
IF sy-subrc NE 0. "如果返回非0，则日期不合法
CALL FUNCTION 'TIME_CHECK_PLAUSIBILITY'