TimeSpan.FromSeconds(Double) precision is inconsistent with the document

[fanruinet]

Description

According to the official document TimeSpan.FromSeconds(Double):

Returns a TimeSpan that represents a specified number of seconds, where the specification is accurate to the nearest millisecond.

But the actual output retained more digits than millisecond.

Reproduction Steps

double paceSpeedInSeconds = 1.5099;
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Expected behavior

Should output (accurate to the nearest millisecond):

00:00:01.5100000
1510

Actual behavior

Outputs:

00:00:01.5099000
1509

Regression?

This is a regression. On .NET Framework 4.8, the actual behavior is consistent with the document:

00:00:01.5100000
1510

Known Workarounds

double paceSpeedInSeconds = Math.Round(1.5099, 3);
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Outputs:

00:00:01.5100000
1510

Configuration

.NET Core 3.1, .NET 5.0, .NET 6.0 on Windows.

Other information

No response

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

Tagging subscribers to this area: @dotnet/area-system-runtime
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

According to the official document TimeSpan.FromSeconds(Double):

Returns a TimeSpan that represents a specified number of seconds, where the specification is accurate to the nearest millisecond.

But the actual output retained more digits than millisecond.

Reproduction Steps

double paceSpeedInSeconds = 1.5099;
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Expected behavior

Should output (accurate to the nearest millisecond):

00:00:01.5100000
1510

Actual behavior

Outputs:

00:00:01.5099000
1509

Regression?

This is a regression. On .NET Framework 4.8, the actual behavior is consistent with the document:

00:00:01.5100000
1510

Known Workarounds

double paceSpeedInSeconds = Math.Round(1.5099, 3);
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Outputs:

00:00:01.5100000
1510

Configuration

.NET Core 3.1, .NET 5.0, .NET 6.0 on Windows.

Other information

No response

Author:	fanruinet
Assignees:	-
Labels:	area-System.Runtime, untriaged
Milestone:	-

Tagging subscribers to this area: @dotnet/area-system-globalization
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

According to the official document TimeSpan.FromSeconds(Double):

Returns a TimeSpan that represents a specified number of seconds, where the specification is accurate to the nearest millisecond.

But the actual output retained more digits than millisecond.

Reproduction Steps

double paceSpeedInSeconds = 1.5099;
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Expected behavior

Should output (accurate to the nearest millisecond):

00:00:01.5100000
1510

Actual behavior

Outputs:

00:00:01.5099000
1509

Regression?

This is a regression. On .NET Framework 4.8, the actual behavior is consistent with the document:

00:00:01.5100000
1510

Known Workarounds

double paceSpeedInSeconds = Math.Round(1.5099, 3);
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Outputs:

00:00:01.5100000
1510

Configuration

.NET Core 3.1, .NET 5.0, .NET 6.0 on Windows.

Other information

No response

Author:	fanruinet
Assignees:	-
Labels:	area-System.Globalization, untriaged
Milestone:	-

[dakersnar]

cc @tarekgh

Tagging subscribers to this area: @dotnet/area-system-runtime
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

According to the official document TimeSpan.FromSeconds(Double):

Returns a TimeSpan that represents a specified number of seconds, where the specification is accurate to the nearest millisecond.

But the actual output retained more digits than millisecond.

Reproduction Steps

double paceSpeedInSeconds = 1.5099;
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Expected behavior

Should output (accurate to the nearest millisecond):

00:00:01.5100000
1510

Actual behavior

Outputs:

00:00:01.5099000
1509

Regression?

This is a regression. On .NET Framework 4.8, the actual behavior is consistent with the document:

00:00:01.5100000
1510

Known Workarounds

double paceSpeedInSeconds = Math.Round(1.5099, 3);
Console.WriteLine(TimeSpan.FromSeconds(paceSpeedInSeconds));
Console.WriteLine(((int)TimeSpan.FromSeconds(paceSpeedInSeconds).TotalMilliseconds));

Outputs:

00:00:01.5100000
1510

Configuration

.NET Core 3.1, .NET 5.0, .NET 6.0 on Windows.

Other information

No response

Author:	fanruinet
Assignees:	-
Labels:	area-System.Runtime, untriaged
Milestone:	-

[tarekgh]

This is intentional change done in the PR dotnet/runtime#1069.

@tannergooding in the PR you mentioned you'll have a breaking change doc. Did you do that? Do you have a link?

@fanruinet feel free to submit a PR https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System/TimeSpan.xml to fix the docs.

[fanruinet]

Thanks, @tarekgh! I found more discussions according to your link. The precision improvement was made here: Improve Precision to 10 microseconds in timespan
Other discussions: AddSeconds and FromSeconds rounding issues

I'm glad to prepare a PR to fix the docs and samples. But I'm not sure how can I fix the docs only for .NET Core 3.0, 3.1, and 5.0+. The docs for .NET Core 2.1 and earlier versions are accurate and should not be changed. @tarekgh, how can I do that?