diff --git a/icu4c/source/i18n/dtitvfmt.cpp b/icu4c/source/i18n/dtitvfmt.cpp
index d308c0454d0..a0bbc15df8f 100644
--- a/icu4c/source/i18n/dtitvfmt.cpp
+++ b/icu4c/source/i18n/dtitvfmt.cpp
@@ -459,10 +459,10 @@ DateIntervalFormat::adoptTimeZone(TimeZone* zone)
     // work clones of that calendar (and should not also be given ownership of the
     // adopted TimeZone).
     if (fFromCalendar) {
-    	fFromCalendar->setTimeZone(*zone);
+        fFromCalendar->setTimeZone(*zone);
     }
     if (fToCalendar) {
-    	fToCalendar->setTimeZone(*zone);
+        fToCalendar->setTimeZone(*zone);
     }
 }
 
@@ -475,10 +475,10 @@ DateIntervalFormat::setTimeZone(const TimeZone& zone)
     // The fDateFormat has the master calendar for the DateIntervalFormat;
     // fFromCalendar and fToCalendar are internal work clones of that calendar.
     if (fFromCalendar) {
-    	fFromCalendar->setTimeZone(zone);
+        fFromCalendar->setTimeZone(zone);
     }
     if (fToCalendar) {
-    	fToCalendar->setTimeZone(zone);
+        fToCalendar->setTimeZone(zone);
     }
 }
 
@@ -1386,25 +1386,21 @@ DateIntervalFormat::fallbackFormat(Calendar& fromCalendar,
     
     UnicodeString fallbackRange;
     MessageFormat::format(fallbackPattern, fmtArray, 2, fallbackRange, status);
+    if ( U_SUCCESS(status) && formatDatePlusTimeRange ) {
+        // fallbackRange has just the time range, need to format the date part and combine that
+        fDateFormat->applyPattern(*fDatePattern);
+        UnicodeString* datePortion = new UnicodeString();
+        otherPos.setBeginIndex(0);
+        otherPos.setEndIndex(0);
+        fDateFormat->format(fromCalendar, *datePortion, otherPos);
+        adjustPosition(*fDateTimeFormat, fallbackRange, pos, *datePortion, otherPos, pos);
+        fmtArray[0].setString(fallbackRange); // {0} is time range
+        fmtArray[1].adoptString(datePortion); // {1} is single date portion
+        fallbackRange.remove();
+        MessageFormat::format(*fDateTimeFormat, fmtArray, 2, fallbackRange, status);
+    }
     if ( U_SUCCESS(status) ) {
-        if (!formatDatePlusTimeRange) {
-            appendTo.append(fallbackRange);
-        } else {
-            // fallbackRange has just the time range, need to format the date part and combine that
-            fDateFormat->applyPattern(*fDatePattern);
-            UnicodeString* datePortion = new UnicodeString();
-            otherPos.setBeginIndex(0);
-            otherPos.setEndIndex(0);
-            fDateFormat->format(fromCalendar, *datePortion, otherPos);
-            adjustPosition(*fDateTimeFormat, fallbackRange, pos, *datePortion, otherPos, pos);
-            fmtArray[0].setString(fallbackRange); // {0} is time range
-            fmtArray[1].adoptString(datePortion); // {1} is single date portion
-            fallbackRange.remove();
-            MessageFormat::format(*fDateTimeFormat, fmtArray, 2, fallbackRange, status);
-            if ( U_SUCCESS(status) ) {
-                appendTo.append(fallbackRange);
-            }
-        }
+        appendTo.append(fallbackRange);
     }
     if (formatDatePlusTimeRange) {
         // restore full pattern
diff --git a/icu4c/source/i18n/unicode/dtitvfmt.h b/icu4c/source/i18n/unicode/dtitvfmt.h
index b91493780d5..4f6fdd0874e 100644
--- a/icu4c/source/i18n/unicode/dtitvfmt.h
+++ b/icu4c/source/i18n/unicode/dtitvfmt.h
@@ -389,6 +389,9 @@ public:
      *                          Result is appended to existing contents.
      * @param fieldPosition     On input: an alignment field, if desired.
      *                          On output: the offsets of the alignment field.
+     *                          There may be multiple instances of a given field type
+     *                          in an interval format; in this case the fieldPosition
+     *                          offsets refer to the first instance.
      * @param status            Output param filled with success/failure status.
      * @return                  Reference to 'appendTo' parameter.
      * @stable ICU 4.0
@@ -408,6 +411,9 @@ public:
      *                          Result is appended to existing contents.
      * @param fieldPosition     On input: an alignment field, if desired.
      *                          On output: the offsets of the alignment field.
+     *                          There may be multiple instances of a given field type
+     *                          in an interval format; in this case the fieldPosition
+     *                          offsets refer to the first instance.
      * @param status            Output param filled with success/failure status.
      * @return                  Reference to 'appendTo' parameter.
      * @stable ICU 4.0
@@ -432,6 +438,9 @@ public:
      *                          Result is appended to existing contents.
      * @param fieldPosition     On input: an alignment field, if desired.
      *                          On output: the offsets of the alignment field.
+     *                          There may be multiple instances of a given field type
+     *                          in an interval format; in this case the fieldPosition
+     *                          offsets refer to the first instance.
      * @param status            Output param filled with success/failure status.
      *                          Caller needs to make sure it is SUCCESS
      *                          at the function entrance
@@ -667,12 +676,20 @@ private:
      */
 
     /**
-     * @param combiningPattern  xxx
-     * @param pat0              xxx
-     * @param pos0              xxx
-     * @param pat1              xxx
-     * @param pos1              xxx
-     * @param posResult         xxx
+     * Provide an updated FieldPosition posResult based on two formats,
+     * the FieldPosition values for each of them, and the pattern used
+     * to combine them. The idea is for posResult to indicate the first
+     * instance (if any) of the specified field in the combined result,
+     * with correct offsets.
+     *
+     * @param combiningPattern  Pattern used to combine pat0 and pat1
+     * @param pat0              Formatted date/time value to replace {0}
+     * @param pos0              FieldPosition within pat0
+     * @param pat1              Formatted date/time value to replace {1}
+     * @param pos1              FieldPosition within pat1
+     * @param posResult         FieldPosition to be set to the correct
+     *                          position of the first field instance when
+     *                          pat0 and pat1 are combined using combiningPattern
      */
     static void
     adjustPosition(UnicodeString& combiningPattern, // has {0} and {1} in it
@@ -681,7 +698,6 @@ private:
                    FieldPosition& posResult);
 
 
-
     /**
      * Format 2 Calendars using fall-back interval pattern
      *
diff --git a/icu4c/source/i18n/unicode/udateintervalformat.h b/icu4c/source/i18n/unicode/udateintervalformat.h
index 5ee92e629af..0b8cb8c9120 100644
--- a/icu4c/source/i18n/unicode/udateintervalformat.h
+++ b/icu4c/source/i18n/unicode/udateintervalformat.h
@@ -1,6 +1,6 @@
 /*
 *****************************************************************************************
-* Copyright (C) 2010-2012, International Business Machines
+* Copyright (C) 2010-2012,2015 International Business Machines
 * Corporation and others. All Rights Reserved.
 *****************************************************************************************
 */
@@ -160,6 +160,9 @@ U_NAMESPACE_END
  *            the beginning and ending indices of field number position->field,
  *            if such a field exists. This parameter may be NULL, in which case
  *            no field position data is returned.
+ *            There may be multiple instances of a given field type in an
+ *            interval format; in this case the position indices refer to the
+ *            first instance.
  * @param status
  *            A pointer to a UErrorCode to receive any errors.
  * @return