Do not show :query completion for possible time entries.

app/src/main/java/org/thoughtcrime/securesms/components/ComposeText.java

@@ -46,6 +46,8 @@ import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import static org.thoughtcrime.securesms.database.MentionUtil.MENTION_STARTER;
 
@@ -54,6 +56,8 @@ public class ComposeText extends EmojiEditText {
   private static final char EMOJI_STARTER       = ':';
   private static final long EMOJI_KEYWORD_DELAY = 1500;
 
+  private static final Pattern TIME_PATTERN = Pattern.compile("^[0-9]{1,2}:[0-9]{1,2}$");
+
   private CharSequence            hint;
   private SpannableString         subHint;
   private MentionRendererDelegate mentionRendererDelegate;
@@ -427,11 +431,37 @@ public class ComposeText extends EmojiEditText {
     }
 
     if (delimiterSearchIndex >= 0 && text.charAt(delimiterSearchIndex) == starter) {
+      if (couldBeTimeEntry(text, delimiterSearchIndex)) {
+        return -1;
+      } else {
         return delimiterSearchIndex + 1;
       }
+    }
     return -1;
   }
 
+  /**
+   * Return true if we think the user may be inputting a time.
+   */
+  private static boolean couldBeTimeEntry(@NonNull CharSequence text, int startIndex) {
+    if (startIndex <= 0 || startIndex + 1 >= text.length()) {
+      return false;
+    }
+
+    int startOfToken = startIndex;
+    while (startOfToken > 0 && !Character.isWhitespace(text.charAt(startOfToken))) {
+      startOfToken--;
+    }
+    startOfToken++;
+
+    int endOfToken = startIndex;
+    while (endOfToken < text.length() && !Character.isWhitespace(text.charAt(endOfToken))) {
+      endOfToken++;
+    }
+
+    return TIME_PATTERN.matcher(text.subSequence(startOfToken, endOfToken)).find();
+  }
+
   private static class CommitContentListener implements InputConnectionCompat.OnCommitContentListener {
 
     private static final String TAG = Log.tag(CommitContentListener.class);