Support more formats in json TimeOnlyConverter

[rofenix2]

Hi, i expected that System.Text.Json.Serialization.Converters.TimeOnlyConverter internally used "TimeOnly.Parse", since trying to parse "19:00" (without seconds) is valid input and one that is frequently used, the same as "7:00 PM" that is the output of TimeOnly.ToShortTimeString(). But neither of them works when trying to deserialize, i think TimeOnlyConverter needs to be a little more consistent with the formats supported by TimeOnly.

runtime/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs

Line 9 in 11ff382

internal sealed class TimeOnlyConverter : JsonPrimitiveConverter<TimeOnly>

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Issue Details

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Hi, i expected that System.Text.Json.Serialization.Converters.TimeOnlyConverter internally used "TimeOnly.Parse", since trying to parse "19:00" (without seconds) is valid input and one that is frequently used, the same as "7:00 PM" that is the output of TimeOnly.ToShortTimeString(). But neither of them works when trying to deserialize, i think TimeOnlyConverter needs to be a little more consistent with the formats supported by TimeOnly.

runtime/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs

Line 9 in 11ff382

internal sealed class TimeOnlyConverter : JsonPrimitiveConverter<TimeOnly>

Author:	cdrfenix
Assignees:	-
Labels:	area-System.Text.Json
Milestone:	-

[svick]

I think that, at least by default, JSON should be treated as a strict, machine-readable format. It should not be treated as something that contains human-readable values and certainly not values that are culture-specific. So TimeOnly.Parse(value) would not be appropriate.

If you need different behavior for your specific use case, can't you write a custom converter?

[rofenix2]

I didnt think about it when i writed this issue, i guess its made to follow the ISO 8601-1:2019 format as specified in this link.

https://learn.microsoft.com/en-us/dotnet/standard/datetime/system-text-json-support?pivots=dotnet-7-0

Ill need to create my own converters for TimeOnly, DateOnly and DateTime for specific culture.

[eiriktsarpalis]

Strict enforcement of formats is by design. The usual recommendation in such cases is to write a custom converter that allows the format you need.