logging: switch time stamps to UTC

Time stamps in local time without explicit time zone are ambigious,
definitely at the end of daylight saving time. Moreover, even
if explicit time zones were given, it is still unconvenient to
correctly sort event expressed in different time zones. However,
with increased use of `just serve`, logs originating from different
machines become the norm. Therefore, normalize all time stamps to
UTC (and explicitly state that this is the time zone used).

1 files changed, 2 insertions, 2 deletions

diff --git a/src/buildtool/logging/log_sink_file.hpp b/src/buildtool/logging/log_sink_file.hpp
index ec9ee257..1ff6ad47 100644
--- a/src/buildtool/logging/log_sink_file.hpp
+++ b/src/buildtool/logging/log_sink_file.hpp
@@ -102,10 +102,10 @@ class LogSinkFile final : public ILogSink {
         timespec ts{};
         clock_gettime(CLOCK_REALTIME, &ts);
         auto timestamp = fmt::format(
-            "{:%Y-%m-%d %H:%M:%S}.{}", fmt::localtime(ts.tv_sec), ts.tv_nsec);
+            "{:%Y-%m-%d %H:%M:%S}.{} UTC", fmt::gmtime(ts.tv_sec), ts.tv_nsec);
 #else
         auto timestamp = fmt::format(
-            "{:%Y-%m-%d %H:%M:%S}", fmt::localtime(std::time(nullptr));
+            "{:%Y-%m-%d %H:%M:%S} UTC", fmt::gmtime(std::time(nullptr));
 #endif
 
         std::ostringstream id{};