public static bool IsValidTimeZoneOffsetString(
string input,
TimeZoneOffset representedOffset)
{
if (input == "Z" && representedOffset.IsUTC)
return true;
else
{
int position = 0;
if (position >= input.Length)
return false; // Empty string
if (input[position] == '+' || input[position] == '-')
{
char sign = input[position];
if (representedOffset.Hours == 0 &&
representedOffset.Minutes == 0 &&
sign == '-')
// Cannot have a negative 00:00 offset.
// That would just be weird.
return false;
position++;
if (position >= input.Length || position + 1 >= input.Length)
return false; // Just a plus sign, or only 1 char after it
string hourChars = new string(
new char[] { input[position], input[position + 1] });
position = position + 2; // Move past hour chars
if (position >= input.Length)
return false; // Nothing after hour chars
else if (input[position] == ':')
position++;
if (position >= input.Length || position + 1 >= input.Length)
return false; // Nothing after hour chars/colon, or
// only one char after it
string minuteChars = new string(
new char[] { input[position], input[position + 1] });
position = position + 2; // Move past minute chars.
if (position < input.Length)
// Position should be past end of string; if it is
// not, the offset string is invalid.
return false;
if (hourChars.All(ch => ParserIdioms.ASCIIDigits.Contains(ch)) &&
minuteChars.All(ch => ParserIdioms.ASCIIDigits.Contains(ch)))
{
// Hour chars and minute chars are all ASCII digits
int hours = int.Parse(hourChars);
int minutes = int.Parse(minuteChars);
if (sign == '-')
{
// Negate hours and minutes if timezone offset
// sign is negative
hours = 0 - hours;
minutes = 0 - minutes;
}
return hours == representedOffset.Hours &&
minutes == representedOffset.Minutes;
}
else
return false;
}
else
// Time zone offset did not begin with a + or -
return false;
}
}
public DateTimeWithTimeZone(DateTime utcDateTime, TimeZoneOffset timeZone)
{
this.utcDateTime = utcDateTime;
this.timeZone = timeZone;
}
