doc/protocol.rst: mention "in seconds" where it was missing

doc/protocol.rst

@@ -414,9 +414,10 @@ Querying :program:`MPD`'s status
     - ``songid``: playlist songid of the current song stopped on or playing
     - ``nextsong`` [#since_0_15]_: playlist song number of the next song to be played
     - ``nextsongid`` [#since_0_15]_: playlist songid of the next song to be played
-    - ``time``: total time elapsed (of current playing/paused song)
+    - ``time``: total time elapsed (of current playing/paused song) in seconds
       (deprecated, use ``elapsed`` instead)
-    - ``elapsed`` [#since_0_16]_: Total time elapsed within the current song, but with higher resolution.
+    - ``elapsed`` [#since_0_16]_: Total time elapsed within the
+      current song in seconds, but with higher resolution.
     - ``duration`` [#since_0_20]_: Duration of the current song in seconds.
     - ``bitrate``: instantaneous bitrate in kbps
     - ``xfade``: ``crossfade`` in seconds
@@ -437,7 +438,7 @@ Querying :program:`MPD`'s status
     - ``albums``: number of albums
     - ``songs``: number of songs
     - ``uptime``: daemon uptime in seconds
-    - ``db_playtime``: sum of all song times in the db
+    - ``db_playtime``: sum of all song times in the database in seconds
     - ``db_update``: last db update in UNIX time
     - ``playtime``: time length of music played