SpringBoot Build info timestamp is truncated to seconds

We use a custom timestamp for the build-info maven goal like this:

...
<properties>
        <maven.build.timestamp.format>yyyy-MM-dd'T'HH:mm:ss.SSS'Z'</maven.build.timestamp.format>
....

<plugins>
...
                        <configuration>
                            <time>${maven.build.timestamp}</time>
                        </configuration>
                        <goals>
                            <goal>repackage</goal>
                            <goal>build-info</goal>
                        </goals>
...

As you can see, the timestamp has sub-second precision and was also printed to the build properties like this:

build.time=2024-12-19T19\:59\:39.040Z

Since Spring Boot 3.3.6 (with this commit), this is effectively truncated to seconds:

build.time=2024-12-19T19\:59\:39Z

This turns out to be a breaking change for us. We can fix our problem by reconfiguring maven.build.timestamp.format to second precision.

So, I don't really expect a fix here, but you may want to add these to the release notes, as this might cause problems when updating.

Comment From: mhalbritter

We call .truncatedTo(ChronoUnit.SECONDS) in org.springframework.boot.maven.MavenBuildOutputTimestamp#toInstant. I wonder if this is necessary.

You also get a timestamp with millis when not setting the time explicitly:

build.time=2024-12-20T09\:51\:23.009Z

Looks like a bug to me.

Comment From: snicoll

Sorry we broke you, closing in favor of PR #43612