diff --git a/lib/src/duration.dart b/lib/src/duration.dart
index 9e256600..6e8ec0c8 100644
--- a/lib/src/duration.dart
+++ b/lib/src/duration.dart
@@ -38,8 +38,10 @@ abstract class ITime {
   static final /*BigInt*/ int maxNanoseconds = (maxDays + 1 /*BigInteger.One*/) * TimeConstants.nanosecondsPerDay - 1;
 
   // 285420 years worth -- we are good for anything;
+  // todo: should this be specific to the Platform?
+  // todo: why was minMillis == -9007199254740993, which is Platform.intMinValueJS-1;
   static const int maxMillis = Platform.intMaxValueJS;
-  static const int minMillis = -9007199254740993; // Utility.intMinValueJS; // was -maxMillis; very shortly was ~maxMillis (which I guess doesn't work well in JS)
+  static const int minMillis = Platform.intMinValueJS; // -9007199254740993; // Utility.intMinValueJS; // was -maxMillis; very shortly was ~maxMillis (which I guess doesn't work well in JS)
 
   static bool isInt64Representable(Time span) => span._isInt64Representable;
   static Time plusSmallNanoseconds(Time span, int nanoseconds) => span._plusSmallNanoseconds(nanoseconds);
diff --git a/lib/src/text/value_cursor.dart b/lib/src/text/value_cursor.dart
index 712e2e0a..ea75284c 100644
--- a/lib/src/text/value_cursor.dart
+++ b/lib/src/text/value_cursor.dart
@@ -126,7 +126,7 @@ class ValueCursor extends TextCursor {
     }
     int count = 0;
     int digit;
-    while (result < 922337203685477580 && (digit = _getDigit()) != -1) {
+    while (result < Platform.valueCursorPrediction && (digit = _getDigit()) != -1) {
       result = result * 10 + digit;
       count++;
       if (!moveNext()) {
@@ -139,8 +139,8 @@ class ValueCursor extends TextCursor {
       return IParseResult.missingNumber<int>(this);
     }
 
-    if (result >= 922337203685477580 && (digit = _getDigit()) != -1) {
-      if (result > 922337203685477580) {
+    if (result >= Platform.valueCursorPrediction && (digit = _getDigit()) != -1) {
+      if (result > Platform.valueCursorPrediction) {
         return _buildNumberOutOfRangeResult<int>(startIndex, tType);
       }
       if (negative && digit == 8) {
diff --git a/lib/src/utility/utilities.dart b/lib/src/utility/utilities.dart
index 6890589d..9bc99882 100644
--- a/lib/src/utility/utilities.dart
+++ b/lib/src/utility/utilities.dart
@@ -38,12 +38,16 @@ abstract class Platform {
   static bool get isWeb => _isWeb ?? dirtyCheck() ?? _isWeb;
   static bool get isVM => _isVM ?? dirtyCheck() ?? _isVM;
 
-  static const intMaxValueJS = 9007199254740992; // math.pow(2, 53);
-  static const intMinValueJS = -9007199254740992; // -math.pow(2, 53); appears to be the same (not 1 more, not 1 less)
-  static const int32MinValue = -2147483648;
-  static const int32MaxValue = 2147483647;
-  static const int64MinValue = -9223372036854775808;
-  static const int64MaxValue = 9223372036854775807;
+  static const int intMaxValueJS = 9007199254740992; // math.pow(2, 53);
+  static const int intMinValueJS = -9007199254740992; // -math.pow(2, 53); appears to be the same (not 1 more, not 1 less)
+  static const int int32MinValue = -2147483648;
+  static const int int32MaxValue = 2147483647;
+
+  // representable in JS and VM: +\- 9223372036854775000 (but, constants in JS must be bounded by intMinValueJS and intMaxValueJS)
+  // Fix for: https://github.com/dart-lang/sdk/issues/33282 <-- bizarre
+  static const int valueCursorPrediction = 13860*66546695792603; // vm: 922337203685477580; js: 922337203685477600
+  static const int int64MinValue = 2147483648 * 2147483648 * -2; // vm: -9223372036854775808; js: -9223372036854776000
+  static const int int64MaxValue = 2147483648 * 2147483648 - 1 + 2147483648 * 2147483648; // vm: 9223372036854775807; js: 9223372036854776000
 
   static int _intMaxValue = isVM ? _intMaxValue = int64MaxValue : _intMaxValue = intMaxValueJS;
   static int _intMinValue = isVM ? _intMinValue = int64MinValue : _intMinValue = intMinValueJS;
@@ -61,15 +65,6 @@ abstract class IDateTimeZoneWriter {
 //
 }
 
-// todo: all of these may affect performance
-
-// todo: only use this for porting... remove all of these later
-@deprecated
-class OutBox<T> {
-  T value;
-  OutBox(this.value);
-}
-
 // https://en.wikipedia.org/wiki/Modulo_operation
 // we should only use this where 'x' can be negative
 int arithmeticMod(num x, int y) {