diff --git a/aos/common/time.cc b/aos/common/time.cc
index 995011a..75ea196 100644
--- a/aos/common/time.cc
+++ b/aos/common/time.cc
@@ -120,6 +120,9 @@
 const Time Time::operator/(int32_t rhs) const {
   return Time(*this) /= rhs;
 }
+double Time::operator/(const Time &rhs) const {
+  return ToSeconds() / rhs.ToSeconds();
+}
 Time &Time::operator%=(int32_t rhs) {
   nsec_ = ToNSec() % rhs;
   const int wraps = nsec_ / kNSecInSec;