Access to the system structure SY is restricted to read access to the following components:
BATCH, DBCNT, FDPOS, INDEX, LANGU, MANDT, MSGID, MSGNO, MSGTY, MSGV1, MSGV2, MSGV3, MSGV4, SYSID, SUBRC, TABIX, and UNAME
Access to all other components is not allowed because they are related to either obsolete or unsupported features.
For more information, see ABAP System Fields in the ABAP Keyword Documentation.
You can use class CL_ABAP_CONTEXT_INFO to retrieve information about the user session, for example, technical user name, business user name, time zone, and so on. The built-in function utclong_current generates a UTC time stamp from the current system time and the current system date in accordance with POSIX standards.
The XCO time library also offers SY representations, especially when it comes to time and date retrieval. For more information about XCO, see Time Library.