How can I format a DateTimeOffset to not have a colon in the timezone offset?

Question

I was reading this MSDocs article about DateTime-related format support https://learn.microsoft.com/en-us/dotnet/standard/datetime/system-text-json-support#support-for-the-iso-8601-12019-format

And I was trying to cast datetime to string with this format without colon in the timezone part:

2021-01-01T14:30:10+0030

I want to cast this datetimeoffset to string. I use this format:

yyyy-MM-ddTHH:mm:sszzz

But the output of the ToString("yyyy-MM-ddTHH:mm:sszzz") method is:

2021-01-01T14:30:10+00:30

It has colon (:) sign in timezone part. How can I cast it like '2021-01-01T14:30:10+0030'? (without colon in the timezone part)

Can I format the timezone part?

Answer 1

It seems it's not possible (in .Net 6 at least) to get a format string for DateTimeOffset to get the required representation. However, you can try combining two formats: date (which is of typeDateTimeOffset) and ints Offset (of type TimeSpan)

string result = $"{date:yyyy-MM-ddTHH:mm:sszz}{date.Offset:mm}"; 

Here we combine

1. date:date:yyyy-MM-ddTHH:mm:sszz - date with Offset up to hours
2. date.Offset:mm - Offset minutes