diff --git a/src/_lib/tzParseTimezone/index.js b/src/_lib/tzParseTimezone/index.js
index 091ed50..03b542c 100644
--- a/src/_lib/tzParseTimezone/index.js
+++ b/src/_lib/tzParseTimezone/index.js
@@ -70,23 +70,32 @@ export default function tzParseTimezone(timezoneString, date, isUtcDate) {
 }
 
 function toUtcDate(date) {
-  return new Date(
-    Date.UTC(
-      date.getFullYear(),
-      date.getMonth(),
-      date.getDate(),
-      date.getHours(),
-      date.getMinutes(),
-      date.getSeconds(),
-      date.getMilliseconds()
-    )
+  return newDateDateUTC(
+    date.getFullYear(),
+    date.getMonth(),
+    date.getDate(),
+    date.getHours(),
+    date.getMinutes(),
+    date.getSeconds(),
+    date.getMilliseconds()
   )
 }
 
+function newDateDateUTC(fullYear, month, day, hour, minute, second, millisecond) {
+  var utcDate = new Date(0)
+  utcDate.setUTCFullYear(fullYear, month, day)
+  utcDate.setUTCHours(hour, minute, second, millisecond)
+  return utcDate
+}
+
+function DateUTC(fullYear, month, day, hour, minute, second, millisecond) {
+  return newDateDateUTC(fullYear, month, day, hour, minute, second, millisecond).getTime()
+}
+
 function calcOffset(date, timezoneString) {
   var tokens = tzTokenizeDate(date, timezoneString)
 
-  var asUTC = Date.UTC(tokens[0], tokens[1] - 1, tokens[2], tokens[3] % 24, tokens[4], tokens[5])
+  var asUTC = DateUTC(tokens[0], tokens[1] - 1, tokens[2], tokens[3] % 24, tokens[4], tokens[5], 0)
 
   var asTS = date.getTime()
   var over = asTS % 1000
diff --git a/src/_lib/tzTokenizeDate/test.js b/src/_lib/tzTokenizeDate/test.js
index 9f4b4f1..c0561a1 100644
--- a/src/_lib/tzTokenizeDate/test.js
+++ b/src/_lib/tzTokenizeDate/test.js
@@ -20,6 +20,11 @@ describe('tzTokenizeDate', function () {
     assert.deepEqual(result, [2020, 1, 23, 0, 0, 0])
   })
 
+  it('works with year < 100', function () {
+    var result = tzTokenizeDate(new Date('0099-01-01T00:00:00.000Z'), 'UTC')
+    assert.deepEqual(result, [99, 1, 1, 0, 0, 0, 0])
+  })
+
   it('returns NaN when the date string is invalid', function () {
     var result = tzTokenizeDate(new Date('2014-10-25T25:46:20Z'), 'UTC')
     assert(Number.isNaN(result[0]))
diff --git a/src/zonedTimeToUtc/index.js b/src/zonedTimeToUtc/index.js
index 5f5cbc1..d7edf06 100644
--- a/src/zonedTimeToUtc/index.js
+++ b/src/zonedTimeToUtc/index.js
@@ -36,15 +36,11 @@ export default function zonedTimeToUtc(date, timeZone, options) {
 
   var d = toDate(date, options)
 
-  var utc = Date.UTC(
-    d.getFullYear(),
-    d.getMonth(),
-    d.getDate(),
-    d.getHours(),
-    d.getMinutes(),
-    d.getSeconds(),
-    d.getMilliseconds()
-  )
+  var tmp = new Date(0)
+  tmp.setUTCFullYear(d.getFullYear(), d.getMonth(), d.getDate())
+  tmp.setUTCHours(d.getHours(), d.getMinutes(), d.getSeconds(), d.getMilliseconds())
+
+  var utc = tmp.getTime()
 
   var offsetMilliseconds = tzParseTimezone(timeZone, new Date(utc))
 
diff --git a/src/zonedTimeToUtc/test.js b/src/zonedTimeToUtc/test.js
index e5d2b5a..7e405bf 100644
--- a/src/zonedTimeToUtc/test.js
+++ b/src/zonedTimeToUtc/test.js
@@ -45,6 +45,18 @@ describe('zonedTimeToUtc', function () {
     assert.deepEqual(result.toISOString(), '2014-06-25T10:00:00.123Z')
   })
 
+  it('works with years < 100 (Date input)', function () {
+    var input = new Date(0)
+    input.setFullYear(99, 0, 1)
+    var result = zonedTimeToUtc(input, 'Europe/Berlin')
+    assert.deepEqual(result.toISOString(), '0099-01-01T00:06:32.000Z')
+  })
+
+  it('works with years < 100 (string input)', function () {
+    var result = zonedTimeToUtc('0099-01-01', 'Europe/Berlin')
+    assert.deepEqual(result.toISOString(), '0098-12-31T23:06:32.000Z')
+  })
+
   describe('near DST changeover (AEST to AEDT)', function () {
     it('zoned time one day before', function () {
       var result = zonedTimeToUtc(