diff --git a/liblog/event.logtags b/liblog/event.logtags
index 301e885..0a3b650 100644
--- a/liblog/event.logtags
+++ b/liblog/event.logtags
@@ -29,6 +29,7 @@
 # 4: Number of allocations
 # 5: Id
 # 6: Percent
+# s: Number of seconds (monotonic time)
 # Default value for data of type int/long is 2 (bytes).
 #
 # TODO: generate ".java" and ".h" files with integer constants from this file.
diff --git a/liblog/event_tag_map.cpp b/liblog/event_tag_map.cpp
index 0b977c2..73ed16f 100644
--- a/liblog/event_tag_map.cpp
+++ b/liblog/event_tag_map.cpp
@@ -229,9 +229,16 @@
   return it->second;
 }
 
+// The position after the end of a valid section of the tag string,
+// caller makes sure delimited appropriately.
+static const char* endOfTag(const char* cp) {
+  while (*cp && (isalnum(*cp) || strchr("_.-@,", *cp))) ++cp;
+  return cp;
+}
+
 // Scan one tag line.
 //
-// "*pData" should be pointing to the first digit in the tag number.  On
+// "pData" should be pointing to the first digit in the tag number.  On
 // successful return, it will be pointing to the last character in the
 // tag line (i.e. the character before the start of the next line).
 //
@@ -241,10 +248,11 @@
 // data and it will outlive the call.
 //
 // Returns 0 on success, nonzero on failure.
-static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
-  char* cp;
-  unsigned long val = strtoul(*pData, &cp, 10);
-  if (cp == *pData) {
+static int scanTagLine(EventTagMap* map, const char*& pData, int lineNum) {
+  char* ep;
+  unsigned long val = strtoul(pData, &ep, 10);
+  const char* cp = ep;
+  if (cp == pData) {
     if (lineNum) {
       fprintf(stderr, OUT_TAG ": malformed tag number on line %d\n", lineNum);
     }
@@ -273,14 +281,13 @@
   }
 
   const char* tag = cp;
-  // Determine whether "c" is a valid tag char.
-  while (isalnum(*++cp) || (*cp == '_')) {
-  }
+  cp = endOfTag(cp);
   size_t tagLen = cp - tag;
 
   if (!isspace(*cp)) {
     if (lineNum) {
-      fprintf(stderr, OUT_TAG ": invalid tag chars on line %d\n", lineNum);
+      fprintf(stderr, OUT_TAG ": invalid tag char %c on line %d\n", *cp,
+              lineNum);
     }
     errno = EINVAL;
     return -1;
@@ -311,9 +318,9 @@
 
   while (*cp != '\n') ++cp;
 #ifdef DEBUG
-  fprintf(stderr, "%d: %p: %.*s\n", lineNum, tag, (int)(cp - *pData), *pData);
+  fprintf(stderr, "%d: %p: %.*s\n", lineNum, tag, (int)(cp - pData), pData);
 #endif
-  *pData = cp;
+  pData = cp;
 
   if (lineNum) {
     if (map->emplaceUnique(tagIndex,
@@ -341,9 +348,9 @@
 
 // Parse the tags out of the file.
 static int parseMapLines(EventTagMap* map, size_t which) {
-  char* cp = static_cast<char*>(map->mapAddr[which]);
+  const char* cp = static_cast<char*>(map->mapAddr[which]);
   size_t len = map->mapLen[which];
-  char* endp = cp + len;
+  const char* endp = cp + len;
 
   // insist on EOL at EOF; simplifies parsing and null-termination
   if (!len || (*(endp - 1) != '\n')) {
@@ -370,7 +377,7 @@
         lineStart = false;
       } else if (isdigit(*cp)) {
         // looks like a tag; scan it out
-        if (scanTagLine(map, &cp, lineNum) != 0) {
+        if (scanTagLine(map, cp, lineNum) != 0) {
           if (!which || (errno != EMLINK)) {
             return -1;
           }
@@ -495,14 +502,13 @@
   int ret = asprintf(&buf, command_template, tag);
   if (ret > 0) {
     // Add some buffer margin for an estimate of the full return content.
-    char* cp;
     size_t size =
         ret - strlen(command_template) +
         strlen("65535\n4294967295\t?\t\t\t?\t# uid=32767\n\n\f?success?");
     if (size > (size_t)ret) {
-      cp = static_cast<char*>(realloc(buf, size));
-      if (cp) {
-        buf = cp;
+      char* np = static_cast<char*>(realloc(buf, size));
+      if (np) {
+        buf = np;
       } else {
         size = ret;
       }
@@ -512,10 +518,12 @@
     // Ask event log tag service for an existing entry
     if (__send_log_msg(buf, size) >= 0) {
       buf[size - 1] = '\0';
-      unsigned long val = strtoul(buf, &cp, 10);        // return size
+      char* ep;
+      unsigned long val = strtoul(buf, &ep, 10);  // return size
+      const char* cp = ep;
       if ((buf != cp) && (val > 0) && (*cp == '\n')) {  // truncation OK
         ++cp;
-        if (!scanTagLine(map, &cp, 0)) {
+        if (!scanTagLine(map, cp, 0)) {
           free(buf);
           return map->find(tag);
         }
@@ -573,8 +581,9 @@
 LIBLOG_ABI_PUBLIC int android_lookupEventTagNum(EventTagMap* map,
                                                 const char* tagname,
                                                 const char* format, int prio) {
-  size_t len = strlen(tagname);
-  if (!len) {
+  const char* ep = endOfTag(tagname);
+  size_t len = ep - tagname;
+  if (!len || *ep) {
     errno = EINVAL;
     return -1;
   }
diff --git a/liblog/logprint.c b/liblog/logprint.c
index 2ade7b0..b62f8b4 100644
--- a/liblog/logprint.c
+++ b/liblog/logprint.c
@@ -326,6 +326,7 @@
   else if (!strcmp(formatString, "uid")) format = FORMAT_MODIFIER_UID;
   else if (!strcmp(formatString, "descriptive")) format = FORMAT_MODIFIER_DESCRIPT;
   /* clang-format on */
+
 #ifndef __MINGW32__
   else {
     extern char* tzname[2];
@@ -637,7 +638,8 @@
   TYPE_MILLISECONDS = '3',
   TYPE_ALLOCATIONS = '4',
   TYPE_ID = '5',
-  TYPE_PERCENT = '6'
+  TYPE_PERCENT = '6',
+  TYPE_MONOTONIC = 's'
 };
 
 static int android_log_printBinaryEvent(const unsigned char** pEventData,
@@ -651,7 +653,7 @@
   size_t outBufLen = *pOutBufLen;
   size_t outBufLenSave = outBufLen;
   unsigned char type;
-  size_t outCount;
+  size_t outCount = 0;
   int result = 0;
   const char* cp;
   size_t len;
@@ -690,6 +692,7 @@
    * 4: Number of allocations
    * 5: Id
    * 6: Percent
+   * s: Number of seconds (monotonic time)
    * Default value for data of type int/long is 2 (bytes).
    */
   if (!cp || !findChar(&cp, &len, '(')) {
@@ -921,6 +924,42 @@
             outCount = snprintf(outBuf, outBufLen, "ms");
           }
           break;
+        case TYPE_MONOTONIC: {
+          static const uint64_t minute = 60;
+          static const uint64_t hour = 60 * minute;
+          static const uint64_t day = 24 * hour;
+
+          /* Repaint as unsigned seconds, minutes, hours ... */
+          outBuf -= outCount;
+          outBufLen += outCount;
+          uint64_t val = lval;
+          if (val >= day) {
+            outCount = snprintf(outBuf, outBufLen, "%" PRIu64 "d ", val / day);
+            if (outCount >= outBufLen) break;
+            outBuf += outCount;
+            outBufLen -= outCount;
+            val = (val % day) + day;
+          }
+          if (val >= minute) {
+            if (val >= hour) {
+              outCount = snprintf(outBuf, outBufLen, "%" PRIu64 ":",
+                                  (val / hour) % (day / hour));
+              if (outCount >= outBufLen) break;
+              outBuf += outCount;
+              outBufLen -= outCount;
+            }
+            outCount =
+                snprintf(outBuf, outBufLen,
+                         (val >= hour) ? "%02" PRIu64 ":" : "%" PRIu64 ":",
+                         (val / minute) % (hour / minute));
+            if (outCount >= outBufLen) break;
+            outBuf += outCount;
+            outBufLen -= outCount;
+          }
+          outCount = snprintf(outBuf, outBufLen,
+                              (val >= minute) ? "%02" PRIu64 : "%" PRIu64 "s",
+                              val % minute);
+        } break;
         case TYPE_ALLOCATIONS:
           outCount = 0;
           /* outCount = snprintf(outBuf, outBufLen, " allocations"); */
diff --git a/logcat/event.logtags b/logcat/event.logtags
index 9f05351..efcc817 100644
--- a/logcat/event.logtags
+++ b/logcat/event.logtags
@@ -30,6 +30,7 @@
 # 4: Number of allocations
 # 5: Id
 # 6: Percent
+# s: Number of seconds (monotonic time)
 # Default value for data of type int/long is 2 (bytes).
 #
 # TODO: generate ".java" and ".h" files with integer constants from this file.
diff --git a/logcat/tests/logcat_test.cpp b/logcat/tests/logcat_test.cpp
index 21868f2..e487a97 100644
--- a/logcat/tests/logcat_test.cpp
+++ b/logcat/tests/logcat_test.cpp
@@ -17,6 +17,7 @@
 #include <ctype.h>
 #include <dirent.h>
 #include <signal.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -31,6 +32,7 @@
 
 #include <android-base/file.h>
 #include <gtest/gtest.h>
+#include <log/event_tag_map.h>
 #include <log/log.h>
 #include <log/log_event_list.h>
 
@@ -47,6 +49,16 @@
 
 #define BIG_BUFFER (5 * 1024)
 
+// rest(), let the logs settle.
+//
+// logd is in a background cgroup and under extreme load can take up to
+// 3 seconds to land a log entry. Under moderate load we can do with 200ms.
+static void rest() {
+    static const useconds_t restPeriod = 200000;
+
+    usleep(restPeriod);
+}
+
 // enhanced version of LOG_FAILURE_RETRY to add support for EAGAIN and
 // non-syscall libs. Since we are only using this in the emergency of
 // a signal to stuff a terminating code into the logs, we will spin rather
@@ -70,7 +82,7 @@
 #undef LOG_TAG
 #define LOG_TAG "inject"
     RLOGE(logcat_executable ".buckets");
-    sleep(1);
+    rest();
 
     ASSERT_TRUE(NULL !=
                 (fp = logcat_popen(
@@ -1412,7 +1424,7 @@
     LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, logcat_regex_prefix,
                                           logcat_regex_prefix "_aaaa"));
     // Let the logs settle
-    sleep(1);
+    rest();
 
     ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
@@ -1450,8 +1462,7 @@
     LOG_FAILURE_RETRY(
         __android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
 
-    // Let the logs settle
-    sleep(1);
+    rest();
 
     ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
@@ -1476,8 +1487,7 @@
 
 static bool End_to_End(const char* tag, const char* fmt, ...) {
     logcat_define(ctx);
-    FILE* fp = logcat_popen(ctx,
-                            "logcat"
+    FILE* fp = logcat_popen(ctx, logcat_executable
                             " -v brief"
                             " -b events"
                             " -v descriptive"
@@ -1523,13 +1533,12 @@
         // Help us pinpoint where things went wrong ...
         fprintf(stderr, "Closest match for\n    %s\n  is\n    %s",
                 expect.c_str(), lastMatch.c_str());
-    } else if (count > 2) {
+    } else if (count > 3) {
         fprintf(stderr, "Too many matches (%d) for %s\n", count, expect.c_str());
     }
 
-    // Expect one the first time around as either liblogcat.descriptive or
-    // logcat.descriptive.  Expect two the second time as the other.
-    return count == 1 || count == 2;
+    // Three different known tests, we can see pollution from the others
+    return count && (count <= 3);
 }
 
 TEST(logcat, descriptive) {
@@ -1537,24 +1546,28 @@
         uint32_t tagNo;
         const char* tagStr;
     };
+    int ret;
 
     {
         static const struct tag hhgtg = { 42, "answer" };
         android_log_event_list ctx(hhgtg.tagNo);
         static const char theAnswer[] = "what is five by seven";
         ctx << theAnswer;
-        ctx.write();
+        // crafted to rest at least once after, and rest between retries.
+        for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+        EXPECT_LE(0, ret);
         EXPECT_TRUE(
             End_to_End(hhgtg.tagStr, "to life the universe etc=%s", theAnswer));
     }
 
     {
         static const struct tag sync = { 2720, "sync" };
-        static const char id[] = "logcat.decriptive";
+        static const char id[] = ___STRING(logcat) ".descriptive-sync";
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << id << (int32_t)42 << (int32_t)-1 << (int32_t)0;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr,
                                    "[id=%s,event=42,source=-1,account=0]", id));
         }
@@ -1563,7 +1576,8 @@
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << id << (int32_t)43 << (int64_t)-1 << (int32_t)0;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "[id=%s,event=43,-1,0]", id));
         }
 
@@ -1571,7 +1585,8 @@
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << id << (int32_t)44 << (int32_t)-1 << (int64_t)0;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             fprintf(stderr, "Expect a \"Closest match\" message\n");
             EXPECT_FALSE(End_to_End(
                 sync.tagStr, "[id=%s,event=44,source=-1,account=0]", id));
@@ -1583,7 +1598,8 @@
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint64_t)30 << (int32_t)2;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(
                 End_to_End(sync.tagStr, "[aggregation time=30ms,count=2]"));
         }
@@ -1591,7 +1607,8 @@
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint64_t)31570 << (int32_t)911;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(
                 End_to_End(sync.tagStr, "[aggregation time=31.57s,count=911]"));
         }
@@ -1602,42 +1619,48 @@
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)512;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=512B"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)3072;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=3KB"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)2097152;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=2MB"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)2097153;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=2097153B"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)1073741824;
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=1GB"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint32_t)3221225472;  // 3MB, but on purpose overflowed
-            ctx.write();
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=-1GB"));
         }
     }
@@ -1645,9 +1668,52 @@
     {
         static const struct tag sync = { 27501, "notification_panel_hidden" };
         android_log_event_list ctx(sync.tagNo);
-        ctx.write();
+        for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+        EXPECT_LE(0, ret);
         EXPECT_TRUE(End_to_End(sync.tagStr, ""));
     }
+
+    {
+        // Invent new entries because existing can not serve
+        EventTagMap* map = android_openEventTagMap(nullptr);
+        ASSERT_TRUE(nullptr != map);
+        static const char name[] = ___STRING(logcat) ".descriptive-monotonic";
+        int myTag = android_lookupEventTagNum(map, name, "(new|1|s)",
+                                              ANDROID_LOG_UNKNOWN);
+        android_closeEventTagMap(map);
+        ASSERT_NE(-1, myTag);
+
+        const struct tag sync = { (uint32_t)myTag, name };
+
+        {
+            android_log_event_list ctx(sync.tagNo);
+            ctx << (uint32_t)7;
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
+            EXPECT_TRUE(End_to_End(sync.tagStr, "new=7s"));
+        }
+        {
+            android_log_event_list ctx(sync.tagNo);
+            ctx << (uint32_t)62;
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
+            EXPECT_TRUE(End_to_End(sync.tagStr, "new=1:02"));
+        }
+        {
+            android_log_event_list ctx(sync.tagNo);
+            ctx << (uint32_t)3673;
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
+            EXPECT_TRUE(End_to_End(sync.tagStr, "new=1:01:13"));
+        }
+        {
+            android_log_event_list ctx(sync.tagNo);
+            ctx << (uint32_t)(86400 + 7200 + 180 + 58);
+            for (ret = -EBUSY; ret == -EBUSY; rest()) ret = ctx.write();
+            EXPECT_LE(0, ret);
+            EXPECT_TRUE(End_to_End(sync.tagStr, "new=1d 2:03:58"));
+        }
+    }
 }
 
 static bool reportedSecurity(const char* command) {
diff --git a/logd/event.logtags b/logd/event.logtags
index 39063a9..fa13a62 100644
--- a/logd/event.logtags
+++ b/logd/event.logtags
@@ -29,6 +29,7 @@
 # 4: Number of allocations
 # 5: Id
 # 6: Percent
+# s: Number of seconds (monotonic time)
 # Default value for data of type int/long is 2 (bytes).
 #
 # TODO: generate ".java" and ".h" files with integer constants from this file.