Time Zone
Definition
Set of rules that dictates the offset of the user's local time from Universal Coordinated Time (UTC).
Use
The local time of a particular user depends on the user's location. The offset of a location from UTC is influenced by
Local Time
The local time in any time zone is calculated in relationship to Greenwich Mean Time (GMT), otherwise known as Universal Coordinated Time or UTC. (Greenwich is a city in the United Kingdom, which is used as the standard for all time zones.)
For example, if the local time in Greenwich (UTC) is 6 p.m., it is 8 hours earlier or 10 a.m. in Los Angeles, which is located in the Pacific time zone. At the same time, it is already 3 a.m. the following morning in Japan, which is 9 hours later than UTC.
Additionally, some time zones observe daylight saving time (DST) and use a "DST rule" for calculation purposes. For these time zones, clocks are normally set forward one hour to make better use of the longer daylight hours in the late spring, summer and early fall.
The determination as to which time zone a particular city or region belongs depends upon both geographical and political factors. The difference between the times of two defined positions on the globe can be up to 24 hours.
Structure
SAP includes rules to accommodate the factors listed above. These rules result in the following structure for a time zone in the system:
The following table describes each part of the structure in more detail.
Time Zone Rules
Part of structure |
Description |
Time zone |
This part includes only the time zone indicator (for example, CET or EST) and a reference to the corresponding time zone rules and daylight saving rules. |
Time zone rule |
This rule defines the offset (+/- hours and minutes) relative to UTC due to geography and political factors. |
DST rule |
This rule defines the offset of daylight saving time relative to standard time (+1 hour). It does not define the start and end dates of daylight saving time (DST). |
Fixed DST rules |
For cases in which daylight saving time is not defined by variable rules, this rule defines the start and end dates of DST for a specific year. |
Variable DST rules |
This rule defines how the system calculates the start and end dates of daylight saving time. You can almost always change this rule and it saves you from having to maintain DST start and end dates every year. |
Rather than distinguishing between two separate time zones (one for standard time and one for daylight saving time), only one time zone indicator is used in the SAP System, which includes the DST rule when applicable.
External Representation
The time zone indicator is a string of up to six characters. Six characters are sufficient for the usual time zone indicators, which can depend on language and platform.
Internal Representation
The time zone indicator's internal and external representations are the same. In addition, the system does not convert between different indicators for the same time zone. For example, in English the acronym for Germany's time zone is CET and in German it is MEZ. For the time zone, the system uses only one indicator that you define. It does not use CET with English-speaking users and MEZ with German-speaking users.
Standardization of the Indicators
You create the time zone indicators in a Customizing table and, therefore, you can maintain them flexibly. This flexibility is necessary because there are no standards for time zone indicators. The indicators depend on the platform, the language and the software. And different terms are often used for DST and standard time in the same time zone (for example, EDT for Eastern Daylight Time and EST for Eastern Standard Time).
Initial Value
Initially, the time zone indicator is blank.