diff --git a/elasticsearch/x-pack/watcher/src/main/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtils.java b/elasticsearch/x-pack/watcher/src/main/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtils.java
index 7266d5ed87c..40651786c1f 100644
--- a/elasticsearch/x-pack/watcher/src/main/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtils.java
+++ b/elasticsearch/x-pack/watcher/src/main/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtils.java
@@ -144,7 +144,7 @@ public class WatcherDateTimeUtils {
         }
         if (token == XContentParser.Token.VALUE_STRING) {
             try {
-                TimeValue value = TimeValue.parseTimeValue(parser.text(), settingName);
+                TimeValue value = parseTimeValueSupportingFractional(parser.text(), settingName);
                 if (value.millis() < 0) {
                     throw new ElasticsearchParseException("could not parse time value [{}]. Time value cannot be negative.", parser.text());
                 }
@@ -158,6 +158,47 @@ public class WatcherDateTimeUtils {
                 "instead", token);
     }
 
+    /**
+     * Parse a {@link TimeValue} with support for fractional values.
+     */
+    public static TimeValue parseTimeValueSupportingFractional(@Nullable String sValue, String settingName) {
+        // This code is lifted almost straight from 2.x's TimeValue.java
+        Objects.requireNonNull(settingName);
+        if (sValue == null) {
+            return null;
+        }
+        try {
+            long millis;
+            String lowerSValue = sValue.toLowerCase(Locale.ROOT).trim();
+            if (lowerSValue.endsWith("ms")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 2)));
+            } else if (lowerSValue.endsWith("s")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 1)) * 1000);
+            } else if (lowerSValue.endsWith("m")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 1)) * 60 * 1000);
+            } else if (lowerSValue.endsWith("h")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 1)) * 60 * 60 * 1000);
+            } else if (lowerSValue.endsWith("d")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 1)) * 24 * 60 * 60 * 1000);
+            } else if (lowerSValue.endsWith("w")) {
+                millis = (long) (Double.parseDouble(lowerSValue.substring(0, lowerSValue.length() - 1)) * 7 * 24 * 60 * 60 * 1000);
+            } else if (lowerSValue.equals("-1")) {
+                // Allow this special value to be unit-less:
+                millis = -1;
+            } else if (lowerSValue.equals("0")) {
+                // Allow this special value to be unit-less:
+                millis = 0;
+            } else {
+                throw new ElasticsearchParseException(
+                        "Failed to parse setting [{}] with value [{}] as a time value: unit is missing or unrecognized",
+                        settingName, sValue);
+            }
+            return new TimeValue(millis, TimeUnit.MILLISECONDS);
+        } catch (NumberFormatException e) {
+            throw new ElasticsearchParseException("Failed to parse [{}]", e, sValue);
+        }
+    }
+
     private static class ClockNowCallable implements Callable<Long> {
 
         private final Clock clock;
diff --git a/elasticsearch/x-pack/watcher/src/test/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtilsTests.java b/elasticsearch/x-pack/watcher/src/test/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtilsTests.java
index 13a2458ccb6..bca06a09dd9 100644
--- a/elasticsearch/x-pack/watcher/src/test/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtilsTests.java
+++ b/elasticsearch/x-pack/watcher/src/test/java/org/elasticsearch/xpack/watcher/support/WatcherDateTimeUtilsTests.java
@@ -7,6 +7,7 @@ package org.elasticsearch.xpack.watcher.support;
 
 
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.Version;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -22,6 +23,7 @@ import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.elasticsearch.xpack.watcher.support.WatcherDateTimeUtils.parseTimeValueSupportingFractional;
 import static org.elasticsearch.xpack.watcher.test.WatcherTestUtils.xContentParser;
 import static org.hamcrest.CoreMatchers.nullValue;
 import static org.hamcrest.Matchers.either;
@@ -122,4 +124,56 @@ public class WatcherDateTimeUtilsTests extends ESTestCase {
         TimeValue parsed = WatcherDateTimeUtils.parseTimeValue(parser, "test");
         assertThat(parsed, nullValue());
     }
+
+    public void testParseTimeValueWithFractional() {
+        assertEquals("This function exists so 5.x can be compatible with 2.x indices. It should be removed with 6.x", 5,
+                Version.CURRENT.major);
+
+        // This code is lifted strait from 2.x's TimeValueTests.java
+        assertEquals(new TimeValue(10, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("10 ms", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("10ms", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("10 MS", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("10MS", "test"));
+
+        assertEquals(new TimeValue(10, TimeUnit.SECONDS), parseTimeValueSupportingFractional("10 s", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.SECONDS), parseTimeValueSupportingFractional("10s", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.SECONDS), parseTimeValueSupportingFractional("10 S", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.SECONDS), parseTimeValueSupportingFractional("10S", "test"));
+
+        assertEquals(new TimeValue(100, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("0.1s", "test"));
+
+        assertEquals(new TimeValue(10, TimeUnit.MINUTES), parseTimeValueSupportingFractional("10 m", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MINUTES), parseTimeValueSupportingFractional("10m", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MINUTES), parseTimeValueSupportingFractional("10 M", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.MINUTES), parseTimeValueSupportingFractional("10M", "test"));
+
+        assertEquals(new TimeValue(10, TimeUnit.HOURS), parseTimeValueSupportingFractional("10 h", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.HOURS), parseTimeValueSupportingFractional("10h", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.HOURS), parseTimeValueSupportingFractional("10 H", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.HOURS), parseTimeValueSupportingFractional("10H", "test"));
+
+        assertEquals(new TimeValue(10, TimeUnit.DAYS), parseTimeValueSupportingFractional("10 d", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.DAYS), parseTimeValueSupportingFractional("10d", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.DAYS), parseTimeValueSupportingFractional("10 D", "test"));
+        assertEquals(new TimeValue(10, TimeUnit.DAYS), parseTimeValueSupportingFractional("10D", "test"));
+
+        assertEquals(new TimeValue(70, TimeUnit.DAYS), parseTimeValueSupportingFractional("10 w", "test"));
+        assertEquals(new TimeValue(70, TimeUnit.DAYS), parseTimeValueSupportingFractional("10w", "test"));
+        assertEquals(new TimeValue(70, TimeUnit.DAYS), parseTimeValueSupportingFractional("10 W", "test"));
+        assertEquals(new TimeValue(70, TimeUnit.DAYS), parseTimeValueSupportingFractional("10W", "test"));
+
+        // Extra fractional tests just because that is the point
+        assertEquals(new TimeValue(100, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("0.1s", "test"));
+        assertEquals(new TimeValue(6, TimeUnit.SECONDS), parseTimeValueSupportingFractional("0.1m", "test"));
+        assertEquals(new TimeValue(6, TimeUnit.MINUTES), parseTimeValueSupportingFractional("0.1h", "test"));
+        assertEquals(new TimeValue(144, TimeUnit.MINUTES), parseTimeValueSupportingFractional("0.1d", "test"));
+        assertEquals(new TimeValue(1008, TimeUnit.MINUTES), parseTimeValueSupportingFractional("0.1w", "test"));
+
+        // And some crazy fractions just for fun
+        assertEquals(new TimeValue(1700, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("1.7s", "test"));
+        assertEquals(new TimeValue(162, TimeUnit.SECONDS), parseTimeValueSupportingFractional("2.7m", "test"));
+        assertEquals(new TimeValue(5988, TimeUnit.MINUTES), parseTimeValueSupportingFractional("99.8h", "test"));
+        assertEquals(new TimeValue(1057968, TimeUnit.SECONDS), parseTimeValueSupportingFractional("12.245d", "test"));
+        assertEquals(new TimeValue(7258204799L, TimeUnit.MILLISECONDS), parseTimeValueSupportingFractional("12.001w", "test"));
+    }
 }