appender: Add offset time setting

[hubertshelley]

Motivation

Solution

[davidbarsky]

The downside of this approach is that the use of a hard-coded offset does not handle daylight savings. I feel that if we're to support non-UTC timestamps inside of tracing-appender, we should use LocalTime to handle this correctly. While that is more expensive call than a UTF offset, it will likely be dwarfed by the file operations happening inside of tracing-appender. What do you think?

[hubertshelley]

The downside of this approach is that the use of a hard-coded offset does not handle daylight savings. I feel that if we're to support non-UTC timestamps inside of tracing-appender, we should use LocalTime to handle this correctly. While that is more expensive call than a UTF offset, it will likely be dwarfed by the file operations happening inside of tracing-appender. What do you think?

我认为，具体偏移时间应该由编码者自主控制，是否需要将偏移时间编写的更灵活一些应该由编码者决定，我们可以提供设置方法。当然这只是我个人的想法。