The Offset type supports the following patterns:
The following standard patterns are supported:
l: Long format, displaying information down to the second.
Typical pattern text: +HH:mm:ssm: Medium format, displaying information down to the minute.
Typical pattern text: +HH:mms: Short format, displaying information down to the hour.
Typical pattern text: +HHL: Long format without punctuation, displaying information down to the second.
Typical pattern text: +HHmmssM: Medium format without punctuation, displaying information down to the minute.
Typical pattern text: +HHmmS: Short format without punctuation, displaying information down to the hour.
Typical pattern text: +HH (so equivalent to s in many cases, but can vary by culture)g: General pattern. Formatting depends on the value passed in. If the offset has seconds, the long
format is used; otherwise, if the offset has minutes, the medium format is used; otherwise the short format is used. When parsing, the other standard format patterns are tried one at a time. This is the default format pattern.G: As g, but using Z for an offset of 0, as if it were Z-prefixed. (See below.)i: As g, but using the colon-free formats (L, M, S)I: As i, but using Z for an offset of 0, as if it were Z-prefixed. (See below.)The following custom pattern characters are supported for offsets. See custom pattern notes for general notes on custom patterns, including characters used for escaping and text literals.
| Character | Meaning | Example | 
Z | 
      This can only occur at the start of a pattern, as a prefix to a normal pattern. When it's used, an offset of zero is always formatted as "Z", and "Z" will be parsed as a zero offset. When formatting, a non-zero offset falls back to the remainder of the pattern. When parsing, a non-Z value is always parsed by the remainder of the pattern, and a result of a zero offset is still acceptable. (So a pattern of "ZHH:mm" can still parse a value of "00:00" even though it would be formatted as "Z".) | 
        Zero: ZHH:mm => Z 5 hours: ZHH:mm => 05:00
       | 
    
H or HH | 
      
        Number of hours in the offset. HH is zero-padded; H is not.
       | 
      
        H:mm => 7:30 HH:mm => 07:30
       | 
    
m or mm | 
      
        Number of minutes within the hour. mm is zero-padded; m is not.
       | 
      
        5 minutes: m:ss => 5:00 5 minutes: mm:ss => 05:00
       | 
    
s or ss | 
      
        Number of seconds within the minute. ss is zero-padded; s is not.
       | 
      
        5 seconds: s => 5 5 seconds: ss => 05
       | 
    
+ | 
      
        The sign of the value, always specified whether positive or negative.
        + and - are always used as the symbols, regardless
        of the culture used when constructing the pattern. A positive offset is used
        when local time is ahead of UTC (e.g. Europe) and a negative offset is used
        when local time is behind UTC (e.g. America).
       | 
      
        Positive value: +HH:mm => +07:30 Negative value: +HH:mm => -07:30
       | 
    
- | 
      
        The sign of the value, only specified when the value is negative.
        + and - are always used as the symbols, regardless
        of the culture used when constructing the pattern.
       | 
      
        Positive value: -HH:mm => 07:30 Negative value: -HH:mm => -07:30
       | 
    
: | 
      The time separator for the format provider; colon in the invariant culture. | HH:mm => 07:30 |