diff --git a/clients/shared/default_value_test.go b/clients/shared/default_value_test.go
index 5119ae6b7..bde1d165f 100644
--- a/clients/shared/default_value_test.go
+++ b/clients/shared/default_value_test.go
@@ -30,13 +30,21 @@ func TestColumn_DefaultValue(t *testing.T) {
 
 	// date
 	dateKind := typing.ETime
-	dateKind.ExtendedTimeDetails = &ext.Date
+	dateNestedKind, err := ext.NewNestedKind(ext.DateKindType, "")
+	assert.NoError(t, err)
+	dateKind.ExtendedTimeDetails = &dateNestedKind
+
 	// time
 	timeKind := typing.ETime
-	timeKind.ExtendedTimeDetails = &ext.Time
+	timeNestedKind, err := ext.NewNestedKind(ext.TimeKindType, "")
+	assert.NoError(t, err)
+	timeKind.ExtendedTimeDetails = &timeNestedKind
+
 	// date time
 	dateTimeKind := typing.ETime
-	dateTimeKind.ExtendedTimeDetails = &ext.TimestampTZ
+	dateTimeNestedKind, err := ext.NewNestedKind(ext.TimestampTZKindType, "")
+	assert.NoError(t, err)
+	dateTimeKind.ExtendedTimeDetails = &dateTimeNestedKind
 
 	testCases := []struct {
 		name                       string
diff --git a/clients/snowflake/dialect/dialect_test.go b/clients/snowflake/dialect/dialect_test.go
index 87647a26d..d377aaf5a 100644
--- a/clients/snowflake/dialect/dialect_test.go
+++ b/clients/snowflake/dialect/dialect_test.go
@@ -180,7 +180,7 @@ func TestSnowflakeDialect_KindForDataType_DateTime(t *testing.T) {
 		for _, expectedDateTime := range expectedDateTimes {
 			kd, err := SnowflakeDialect{}.KindForDataType(expectedDateTime, "")
 			assert.NoError(t, err)
-			assert.Equal(t, ext.TimestampTZ.Type, kd.ExtendedTimeDetails.Type, expectedDateTime)
+			assert.Equal(t, ext.TimestampTZKindType, kd.ExtendedTimeDetails.Type, expectedDateTime)
 		}
 	}
 	{
@@ -189,7 +189,7 @@ func TestSnowflakeDialect_KindForDataType_DateTime(t *testing.T) {
 		for _, expectedDateTime := range expectedDateTimes {
 			kd, err := SnowflakeDialect{}.KindForDataType(expectedDateTime, "")
 			assert.NoError(t, err)
-			assert.Equal(t, ext.TimestampNTZ.Type, kd.ExtendedTimeDetails.Type, expectedDateTime)
+			assert.Equal(t, ext.TimestampNTZKindType, kd.ExtendedTimeDetails.Type, expectedDateTime)
 		}
 	}
 }
diff --git a/lib/debezium/converters/time.go b/lib/debezium/converters/time.go
index 97a01e71f..70b7f236a 100644
--- a/lib/debezium/converters/time.go
+++ b/lib/debezium/converters/time.go
@@ -11,18 +11,22 @@ import (
 
 type Time struct{}
 
-func (Time) ToKindDetails() typing.KindDetails {
-	return typing.NewExtendedTimeDetails(typing.ETime, ext.TimeKindType, "")
+func (Time) layout() string {
+	return "15:04:05.000"
+}
+
+func (t Time) ToKindDetails() typing.KindDetails {
+	return typing.NewExtendedTimeDetails(typing.ETime, ext.TimeKindType, t.layout())
 }
 
-func (Time) Convert(val any) (any, error) {
+func (t Time) Convert(val any) (any, error) {
 	valInt64, isOk := val.(int64)
 	if !isOk {
 		return nil, fmt.Errorf("expected int64 got '%v' with type %T", val, val)
 	}
 
 	// Represents the number of milliseconds past midnight, and does not include timezone information.
-	return ext.NewExtendedTime(time.UnixMilli(valInt64).In(time.UTC), ext.TimeKindType, ""), nil
+	return ext.NewExtendedTime(time.UnixMilli(valInt64).In(time.UTC), ext.TimeKindType, t.layout()), nil
 }
 
 type NanoTime struct{}
diff --git a/lib/debezium/converters/time_test.go b/lib/debezium/converters/time_test.go
index 15ec2e88d..461a4312f 100644
--- a/lib/debezium/converters/time_test.go
+++ b/lib/debezium/converters/time_test.go
@@ -124,13 +124,21 @@ func TestZonedTimestamp_Convert(t *testing.T) {
 }
 
 func TestTime_Convert(t *testing.T) {
+	{
+		val, err := Time{}.Convert(int64(54720321))
+		assert.NoError(t, err)
+
+		extTime, isOk := val.(*ext.ExtendedTime)
+		assert.True(t, isOk)
+		assert.Equal(t, "15:12:00.321", extTime.String(""))
+	}
 	{
 		val, err := Time{}.Convert(int64(54720000))
 		assert.NoError(t, err)
 
 		extTime, isOk := val.(*ext.ExtendedTime)
 		assert.True(t, isOk)
-		assert.Equal(t, "15:12:00+00", extTime.String(""))
+		assert.Equal(t, "15:12:00.000", extTime.String(""))
 	}
 }
 
diff --git a/lib/debezium/schema_test.go b/lib/debezium/schema_test.go
index c8ba9c724..5fcb338fb 100644
--- a/lib/debezium/schema_test.go
+++ b/lib/debezium/schema_test.go
@@ -254,13 +254,20 @@ func TestField_ToKindDetails(t *testing.T) {
 		}
 	}
 	{
-		// Time
-		for _, dbzType := range []SupportedDebeziumType{Time, TimeKafkaConnect, TimeWithTimezone} {
-			kd, err := Field{DebeziumType: dbzType}.ToKindDetails()
+		{
+			// Time with timezone
+			kd, err := Field{DebeziumType: TimeWithTimezone}.ToKindDetails()
 			assert.NoError(t, err)
-			assert.Equal(t, typing.NewExtendedTimeDetails(typing.ETime, ext.TimeKindType, ""), kd, dbzType)
+			assert.Equal(t, typing.NewExtendedTimeDetails(typing.ETime, ext.TimeKindType, ""), kd)
+		}
+		{
+			// Time
+			for _, dbzType := range []SupportedDebeziumType{Time, TimeKafkaConnect} {
+				kd, err := Field{DebeziumType: dbzType}.ToKindDetails()
+				assert.NoError(t, err)
+				assert.Equal(t, typing.NewExtendedTimeDetails(typing.ETime, ext.TimeKindType, "15:04:05.000"), kd, dbzType)
+			}
 		}
-
 		{
 			// Micro time
 			kd, err := Field{DebeziumType: MicroTime}.ToKindDetails()
diff --git a/lib/optimization/table_data_merge_columns_test.go b/lib/optimization/table_data_merge_columns_test.go
index 31c9cce08..390024362 100644
--- a/lib/optimization/table_data_merge_columns_test.go
+++ b/lib/optimization/table_data_merge_columns_test.go
@@ -55,7 +55,10 @@ func TestTableData_UpdateInMemoryColumnsFromDestination(t *testing.T) {
 		tableData.AddInMemoryCol(columns.NewColumn("foo", typing.String))
 
 		extTime := typing.ETime
-		extTime.ExtendedTimeDetails = &ext.Date
+		nestedKind, err := ext.NewNestedKind(ext.DateKindType, "")
+		assert.NoError(t, err)
+
+		extTime.ExtendedTimeDetails = &nestedKind
 		tsCol := columns.NewColumn("foo", extTime)
 		assert.NoError(t, tableData.MergeColumnsFromDestination(tsCol))
 
diff --git a/lib/optimization/table_data_test.go b/lib/optimization/table_data_test.go
index 79eaa0243..c54cc1b9f 100644
--- a/lib/optimization/table_data_test.go
+++ b/lib/optimization/table_data_test.go
@@ -166,7 +166,7 @@ func TestTableData_UpdateInMemoryColumns(t *testing.T) {
 
 	col, isOk := tableData.ReadOnlyInMemoryCols().GetColumn("CHANGE_me")
 	assert.True(t, isOk)
-	assert.Equal(t, ext.TimestampTZ.Type, col.KindDetails.ExtendedTimeDetails.Type)
+	assert.Equal(t, ext.TimestampTZKindType, col.KindDetails.ExtendedTimeDetails.Type)
 
 	// It went from invalid to boolean.
 	col, isOk = tableData.ReadOnlyInMemoryCols().GetColumn("bar")
diff --git a/lib/parquetutil/parse_values_test.go b/lib/parquetutil/parse_values_test.go
index b4c30f67c..ddf2cce0e 100644
--- a/lib/parquetutil/parse_values_test.go
+++ b/lib/parquetutil/parse_values_test.go
@@ -58,7 +58,10 @@ func TestParseValue(t *testing.T) {
 	{
 		// Time
 		eTime := typing.ETime
-		eTime.ExtendedTimeDetails = &ext.Time
+		nestedKind, err := ext.NewNestedKind(ext.TimeKindType, "")
+		assert.NoError(t, err)
+
+		eTime.ExtendedTimeDetails = &nestedKind
 		value, err := ParseValue("03:15:00", columns.NewColumn("", eTime))
 		assert.NoError(t, err)
 		assert.Equal(t, "03:15:00+00", value)
@@ -66,7 +69,10 @@ func TestParseValue(t *testing.T) {
 	{
 		// Date
 		eDate := typing.ETime
-		eDate.ExtendedTimeDetails = &ext.Date
+		nestedKind, err := ext.NewNestedKind(ext.DateKindType, "")
+		assert.NoError(t, err)
+
+		eDate.ExtendedTimeDetails = &nestedKind
 		value, err := ParseValue("2022-12-25", columns.NewColumn("", eDate))
 		assert.NoError(t, err)
 		assert.Equal(t, "2022-12-25", value)
@@ -74,7 +80,10 @@ func TestParseValue(t *testing.T) {
 	{
 		// Timestamp TZ
 		eDateTime := typing.ETime
-		eDateTime.ExtendedTimeDetails = &ext.TimestampTZ
+		nestedKind, err := ext.NewNestedKind(ext.TimestampTZKindType, "")
+		assert.NoError(t, err)
+
+		eDateTime.ExtendedTimeDetails = &nestedKind
 		value, err := ParseValue("2023-04-24T17:29:05.69944Z", columns.NewColumn("", eDateTime))
 		assert.NoError(t, err)
 		assert.Equal(t, int64(1682357345699), value)
diff --git a/lib/typing/ext/parse.go b/lib/typing/ext/parse.go
index ee8dae50d..909bd929f 100644
--- a/lib/typing/ext/parse.go
+++ b/lib/typing/ext/parse.go
@@ -50,7 +50,12 @@ func ParseExtendedDateTime(value string, kindType ExtendedTimeKindType) (*Extend
 
 		// If that doesn't work, try timestamp
 		if et, err := parseDateTime(value); err == nil {
-			et.nestedKind = Date
+			nestedKind, err := NewNestedKind(DateKindType, "")
+			if err != nil {
+				return nil, err
+			}
+
+			et.nestedKind = nestedKind
 			return et, nil
 		}
 	case TimeKindType:
@@ -61,7 +66,12 @@ func ParseExtendedDateTime(value string, kindType ExtendedTimeKindType) (*Extend
 
 		// If that doesn't work, try timestamp
 		if et, err := parseDateTime(value); err == nil {
-			et.nestedKind = Time
+			nestedKind, err := NewNestedKind(TimeKindType, "")
+			if err != nil {
+				return nil, err
+			}
+
+			et.nestedKind = nestedKind
 			return et, nil
 		}
 	}
diff --git a/lib/typing/ext/time.go b/lib/typing/ext/time.go
index ebe5a6a8a..d84c2ea5b 100644
--- a/lib/typing/ext/time.go
+++ b/lib/typing/ext/time.go
@@ -2,12 +2,10 @@ package ext
 
 import (
 	"cmp"
-	"encoding/json"
+	"fmt"
 	"time"
 )
 
-// TODO: This package should have a concept of default formats for each type.
-
 type ExtendedTimeKindType string
 
 const (
@@ -17,32 +15,34 @@ const (
 	TimeKindType         ExtendedTimeKindType = "time"
 )
 
+func (e ExtendedTimeKindType) defaultLayout() (string, error) {
+	switch e {
+	case TimestampTZKindType:
+		return time.RFC3339Nano, nil
+	case TimestampNTZKindType:
+		return RFC3339NanosecondNoTZ, nil
+	case DateKindType:
+		return PostgresDateFormat, nil
+	case TimeKindType:
+		return PostgresTimeFormat, nil
+	default:
+		return "", fmt.Errorf("unknown kind type: %q", e)
+	}
+}
+
 type NestedKind struct {
 	Type   ExtendedTimeKindType
 	Format string
 }
 
-var (
-	TimestampNTZ = NestedKind{
-		Type:   TimestampNTZKindType,
-		Format: RFC3339NanosecondNoTZ,
-	}
-
-	TimestampTZ = NestedKind{
-		Type:   TimestampTZKindType,
-		Format: time.RFC3339Nano,
+func NewNestedKind(kindType ExtendedTimeKindType, optionalFormat string) (NestedKind, error) {
+	defaultLayout, err := kindType.defaultLayout()
+	if err != nil {
+		return NestedKind{}, err
 	}
 
-	Date = NestedKind{
-		Type:   DateKindType,
-		Format: PostgresDateFormat,
-	}
-
-	Time = NestedKind{
-		Type:   TimeKindType,
-		Format: PostgresTimeFormat,
-	}
-)
+	return NestedKind{Type: kindType, Format: cmp.Or(optionalFormat, defaultLayout)}, nil
+}
 
 // ExtendedTime is created because Golang's time.Time does not allow us to explicitly cast values as a date, or time
 // and only allows timestamp expressions.
@@ -51,29 +51,25 @@ type ExtendedTime struct {
 	nestedKind NestedKind
 }
 
+// MarshalJSON is a custom JSON marshaller for ExtendedTime.
+// This is only used for nested MongoDB objects where there may be nested DateTime values.
 func (e ExtendedTime) MarshalJSON() ([]byte, error) {
-	return json.Marshal(e.String(""))
+	// This is consistent with how MongoDB's Go driver marshals time.Time
+	return e.ts.UTC().MarshalJSON()
 }
 
+// TODO: Have this return an error instead of nil
 func NewExtendedTime(t time.Time, kindType ExtendedTimeKindType, originalFormat string) *ExtendedTime {
-	if originalFormat == "" {
-		switch kindType {
-		case TimestampTZKindType:
-			originalFormat = TimestampTZ.Format
-		case TimestampNTZKindType:
-			originalFormat = TimestampNTZ.Format
-		case DateKindType:
-			originalFormat = Date.Format
-		case TimeKindType:
-			originalFormat = Time.Format
-		}
+	defaultLayout, err := kindType.defaultLayout()
+	if err != nil {
+		return nil
 	}
 
 	return &ExtendedTime{
 		ts: t,
 		nestedKind: NestedKind{
 			Type:   kindType,
-			Format: originalFormat,
+			Format: cmp.Or(originalFormat, defaultLayout),
 		},
 	}
 }
diff --git a/lib/typing/ext/time_test.go b/lib/typing/ext/time_test.go
index be574670c..4963ed24a 100644
--- a/lib/typing/ext/time_test.go
+++ b/lib/typing/ext/time_test.go
@@ -15,7 +15,7 @@ func TestExtendedTime_MarshalJSON(t *testing.T) {
 		// Single value
 		bytes, err := json.Marshal(extTime)
 		assert.NoError(t, err)
-		assert.Equal(t, `"2025-09-13T00:00:00.123Z"`, string(bytes))
+		assert.Equal(t, `"2025-09-13T00:00:00.123456Z"`, string(bytes))
 	}
 	{
 		// As a nested object
@@ -30,6 +30,6 @@ func TestExtendedTime_MarshalJSON(t *testing.T) {
 
 		bytes, err := json.Marshal(obj)
 		assert.NoError(t, err)
-		assert.Equal(t, `{"extendedTime":"2025-09-13T00:00:00.123Z","foo":"bar"}`, string(bytes))
+		assert.Equal(t, `{"extendedTime":"2025-09-13T00:00:00.123456Z","foo":"bar"}`, string(bytes))
 	}
 }
diff --git a/lib/typing/mongo/bson_test.go b/lib/typing/mongo/bson_test.go
index 82d440099..500ce2cc4 100644
--- a/lib/typing/mongo/bson_test.go
+++ b/lib/typing/mongo/bson_test.go
@@ -125,6 +125,7 @@ func TestJSONEToMap(t *testing.T) {
 		extendedTime, isOk := result["test_timestamp"]
 		assert.True(t, isOk)
 		assert.Equal(t, ext.NewExtendedTime(time.Date(2023, time.March, 16, 1, 18, 37, 0, time.UTC), ext.TimestampTZKindType, ext.ISO8601), extendedTime)
+		assert.Equal(t, "2023-03-16T01:18:37+00:00", extendedTime.(*ext.ExtendedTime).String(""))
 	}
 	{
 		// Boolean
@@ -143,7 +144,7 @@ func TestJSONEToMap(t *testing.T) {
 		// Nested object
 		value, err := json.Marshal(result["test_nested_object"])
 		assert.NoError(t, err)
-		assert.Equal(t, `{"a":{"b":{"c":"hello"}},"super_nested":{"foo":"bar","test_timestamp":"2023-03-16T01:18:37+00:00"},"test_timestamp":"2023-03-16T01:18:37+00:00"}`, string(value))
+		assert.Equal(t, `{"a":{"b":{"c":"hello"}},"super_nested":{"foo":"bar","test_timestamp":"2023-03-16T01:18:37Z"},"test_timestamp":"2023-03-16T01:18:37Z"}`, string(value))
 	}
 	{
 		// NaN
@@ -222,6 +223,7 @@ func TestBsonValueToGoValue(t *testing.T) {
 		extendedTime, isOk := result.(*ext.ExtendedTime)
 		assert.True(t, isOk)
 		assert.Equal(t, ext.NewExtendedTime(time.Date(2021, time.January, 1, 0, 0, 0, 0, time.UTC), ext.TimestampTZKindType, ext.ISO8601), extendedTime)
+		assert.Equal(t, "2021-01-01T00:00:00+00:00", extendedTime.String(""))
 	}
 	{
 		// primitive.ObjectID