diff --git a/src/timer.cpp b/src/timer.cpp
index f97449e797..409135cbaf 100644
--- a/src/timer.cpp
+++ b/src/timer.cpp
@@ -249,8 +249,8 @@ void Timer::modify_params(int narg, char **arg)
     // format timeout setting
     std::string timeout = "off";
     if (_timeout >= 0) {
-      std::time_t tv = _timeout;
-      timeout = fmt::format("{:%H:%M:%S}", fmt::gmtime(tv));
+      std::tm tv = fmt::gmtime((std::time_t) _timeout);
+      timeout = fmt::format("{:02d}:{:%M:%S}", tv.tm_yday * 24 + tv.tm_hour, tv);
     }
 
     utils::logmesg(lmp, "New timer settings: style={}  mode={}  timeout={}\n", timer_style[_level],