Skip to content

Add note about omitted fractional-second digits when formatting DT(Offset)s in System.Text.Json #16863

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jan 28, 2020
Merged

Add note about omitted fractional-second digits when formatting DT(Offset)s in System.Text.Json #16863

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7c0a577
Add note about ommited fractional seconds when formatting DT(Offset)s…
layomia Jan 27, 2020
1bf93be
Address review feedback
layomia Jan 28, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 17 additions & 1 deletion docs/standard/datetime/system-text-json-support.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -222,4 +222,20 @@ The following levels of granularity are defined for formatting:

Used to format a <xref:System.DateTime> or <xref:System.DateTimeOffset> with fractional seconds and with a local offset.

If present, a maximum of 7 fractional digits are written. This aligns with the <xref:System.DateTime> implementation, which is limited to this resolution.
If the [round-trip format](../base-types/standard-date-and-time-format-strings.md#the-round-trip-o-o-format-specifier) representation of a
<xref:System.DateTime> or <xref:System.DateTimeOffset> instance has trailing zeros in its fractional seconds, then <xref:System.Text.Json.JsonSerializer>
and <xref:System.Text.Json.Utf8JsonWriter> will format a representation of the instance without trailing zeros.
For example, a <xref:System.DateTime> instance whose [round-trip format](../base-types/standard-date-and-time-format-strings.md#the-round-trip-o-o-format-specifier)
representation is `2019-04-24T14:50:17.1010000Z`, will be formatted as `2019-04-24T14:50:17.101Z` by <xref:System.Text.Json.JsonSerializer>
and <xref:System.Text.Json.Utf8JsonWriter>.

If the [round-trip format](../base-types/standard-date-and-time-format-strings.md#the-round-trip-o-o-format-specifier) representation of a
<xref:System.DateTime> or <xref:System.DateTimeOffset> instance has all zeros in its fractional seconds, then <xref:System.Text.Json.JsonSerializer>
and <xref:System.Text.Json.Utf8JsonWriter> will format a representation of the instance without fractional seconds.
For example, a <xref:System.DateTime> instance whose [round-trip format](../base-types/standard-date-and-time-format-strings.md#the-round-trip-o-o-format-specifier)
representation is `2019-04-24T14:50:17.0000000+02:00`, will be formatted as `2019-04-24T14:50:17+02:00` by <xref:System.Text.Json.JsonSerializer>
and <xref:System.Text.Json.Utf8JsonWriter>.

Truncating zeros in fractional-second digits allows the smallest output needed to preserve information on a round trip to be written.

A maximum of 7 fractional-second digits are written. This aligns with the <xref:System.DateTime> implementation, which is limited to this resolution.