Display the build date in the editor and when starting the engine

This can be used to quickly see how recent a development build is,
without having to look up the commit date manually.
When juggling around with various builds (e.g. for benchmarking),
this can also be used to ensure that you're actually running the
binary you intended to run.

The date stored is the date of the Git commit that is built, not
the current date at the time of building the binary. This ensures
binaries can remain reproducible.

The version timestamp can be accessed using the `timestamp` key
of the `Engine.get_version_info()` return value.

1 files changed, 9 insertions, 1 deletions

diff --git a/editor/editor_about.cpp b/editor/editor_about.cpp
index b4ef0f8c4a..e594d53d69 100644
--- a/editor/editor_about.cpp
+++ b/editor/editor_about.cpp
@@ -33,6 +33,7 @@
 #include "core/authors.gen.h"
 #include "core/donors.gen.h"
 #include "core/license.gen.h"
+#include "core/os/time.h"
 #include "core/version.h"
 #include "editor/editor_string_names.h"
 #include "editor/themes/editor_scale.h"
@@ -206,7 +207,14 @@ EditorAbout::EditorAbout() {
 	// Set the text to copy in metadata as it slightly differs from the button's text.
 	version_btn->set_meta(META_TEXT_TO_COPY, "v" VERSION_FULL_BUILD + hash);
 	version_btn->set_underline_mode(LinkButton::UNDERLINE_MODE_ON_HOVER);
-	version_btn->set_tooltip_text(TTR("Click to copy."));
+	String build_date;
+	if (VERSION_TIMESTAMP > 0) {
+		build_date = Time::get_singleton()->get_datetime_string_from_unix_time(VERSION_TIMESTAMP, true) + " UTC";
+	} else {
+		build_date = TTR("(unknown)");
+	}
+	version_btn->set_tooltip_text(vformat(TTR("Git commit date: %s\nClick to copy the version number."), build_date));
+
 	version_btn->connect("pressed", callable_mp(this, &EditorAbout::_version_button_pressed));
 	version_info_vbc->add_child(version_btn);