This describes the time zone and the daylight saving time (DST).
Concepts of Time Zone and DST
Time zone
There are 24 time zones all over the world. They are neutral time zone (zero time zone), GMT+8 time zones 1-12, and GMT-8 time zones 1-12. Each time zone spans 15 degrees of longitude, which is equal to one hour in time. GMT+8 time zone 12 and GMT-8 time zone 12 each span 7.5 degrees of longitude with the boundary at 180 degrees east longitude and 180 degrees west longitude. The time on the central longitude line of each time zone is the time used by the whole time zone, which is called zone time.
DST
DST is a statutory time. The daytime is long in summer. To save resources and make full use of daylight time, some countries determine the summer time in the form of law. In summer, the time is adjusted one hour forward or half hour or several hours forward. In winter, the time is set back.
Setting the Time Zone and the DST
When configuring BSC data, you must configure the time zone and the DST.
Time zone configuration
Set the time zone where the BSC is located. The value ranges from GMT-12:00 to GMT+14:00. The time zone in Venezuela must be set to GMT-4:30.
DST configuration
Set the time when the DST starts and ends. Set the deviation of the DST.
The DST can be set to a date, a week day, or a combination of date and week day.
Date: The DST starts or ends on a certain day. Week day: The DST starts or ends on a certain week day of a month. Mix: The DST starts or ends on a certain weekday after a certain day.
NOTE: If you set the DST to the mixture of the date and week day, the date must be in the current month, and the specified day plus six should not exceed the last day of the current month. For example, if you select Mix and February, the specified day must be within 1-22.
- The start month and the end month of the daylight saving time must be different. You can set the start time and the end time of the DST in different modes. Due to the time difference between the northern hemisphere and the southern hemisphere, the value of the start time may be greater than the value of the end time.
- The unit of the DST deviation is minute. The deviation must contain 30 minutes. The value range is from 0 to 120.
CAUTION: After the time zone is modified, the running of some timing tasks on the server may be incorrect. If the resetting of the server core process does not have too much influence, for example, during the initial installation, Huawei recommends that you reset the server core process after modifying the time zone.
After the time zone is modified, the results of the performance measurement in the current granularity period and in the next granularity period may be incorrect (unreliable or missing).
After the time zone is modified, the CPU usage of some boards may increase. Huawei recommends that you modify the time zone when the traffic volume is low, for example, at night.