System Time Zone and User Time Zone
- The system time zone is the time zone of the system time and the system date and cannot be changed while the system is running. It is contained in the column TZONESYS in the database table TTZCU.
- The user time zone is a time zone that can be defined for the
user time and
user date of each individual user in the
user master record. It is contained in the system field
Both time zones are displayed in transaction SU01 on the Fixed
Values tab, however only the user time zone can be changed here. This requires a new logon to
take effect. If no user time zone is defined in the user master record, or the specified time zone is
invalid or inactive, the default value from the column TZONEDEF in the database table TTZCU
is used. If it is invalid or inactive, the system field
sy-zonlo is filled with blanks.
System Time and System Date
The system time and the system date are the local time and local date in AS ABAP in the system time zone. They are produced by regular synchronizations between the clock of the ABAP runtime server and the clock of the database server. During the synchronization process, the ABAP runtime environment clock is set to the database server clock. Since this happens on all application servers in AS ABAP, the ABAP runtime environment clock is synchronized with the clocks on all other application servers and with the database system clock, and therefore shows the system time and system date of the entire AS ABAP.
The character-like system fields
sy-datum are provided with the system time and system date at certain times.
From a technical perspective, the ABAP runtime environment clock is synchronized with the database server clock on request. If a time is required (for example, to populate system fields for date and time), the system checks whether the last synchronization was performed during the specified interval. If this is not the case, synchronization is performed.
User Time and User Date
The user time and the user date are the local time and local date of the current user, calculated from the system time and the user time zone. The
character-like system fields
sy-datlo are provided with the user time and user date at certain times.
sy-zonlo is initial,
are given the same values as
sy-datum, the system time and system date.
To get the local time and local date from a
UTC time stamp created using GET
TIME STAMP, the content of the system field
sy-zonlo can be passed
to the statement CONVERT TIME
STAMP. An initial value for the time zone is set in
CONVERT TIME STAMP, but set implicitly to "UTC" and not to the system time zone.