src/java.base/share/classes/java/time/LocalTime.java

@@ -1486,10 +1486,25 @@
         total += minute * NANOS_PER_MINUTE;
         total += second * NANOS_PER_SECOND;
         total += nano;
         return total;
     }
+    /**
+     * Converts this {@code LocalTime} to the number of seconds since the epoch
+     * of 1970-01-01T00:00:00Z.
+     * <p>
+     * This returns the number of seconds from the epoch for this {@link LocalTime}.
+     *
+     * @param offset the zone offset, not null
+     * @return the number of seconds since the epoch of 1970-01-01T00:00:00Z, may be negative
+     */
+    public int toEpochSecond(ZoneOffset offset) {
+        Objects.requireNonNull(offset, "offset");
+        int secs = toSecondOfDay();
+        secs -= offset.getTotalSeconds();
+        return secs;
+    }
 
     //-----------------------------------------------------------------------
     /**
      * Compares this time to another time.
      * <p>