changed the default to truncate

that’s probably the more common case

map.go

@@ -191,22 +191,22 @@ func EmptyMapValuesMatchAny() ContainsOption {
 // to parse any string values back into time.Time values.  This allows correct processing of
 // the time.Time zero values.
 //
-// If rounding is > 0, times will be rounded.  If ignoreTimeZone is true, the location data will
+// If truncation is > 0, times will be truncation.  If ignoreTimeZone is true, the location data will
 // be stripped off the time values before comparison.
-func ParseDates(rounding time.Duration, ignoreTimeZone bool) ContainsOption {
+func ParseDates(truncation time.Duration, ignoreTimeZone bool) ContainsOption {
 	return func(o *containsOptions) {
 		o.parseDates = true
-		o.roundDates = rounding
+		o.truncateDates = truncation
 		o.stripTimeZone = ignoreTimeZone
 	}
 }
 
-// TruncateDates is like ParseDates, but truncates time values rather than rounding them.
+// RoundDates is like ParseDates, but rounds time values rather than truncating them.
 // If both options are specified, truncation will be applied first.
-func TruncateDates(truncation time.Duration, ignoreTimeZone bool) ContainsOption {
+func RoundDates(rounding time.Duration, ignoreTimeZone bool) ContainsOption {
 	return func(o *containsOptions) {
 		o.parseDates = true
-		o.truncateDates = truncation
+		o.roundDates = rounding
 		o.stripTimeZone = ignoreTimeZone
 	}
 }

maps_test.go

@@ -336,24 +336,24 @@ func TestContains(t *testing.T) {
 			expected: false,
 		},
 		{
-			name:     "rounddates",
-			v1:       map[string]interface{}{"t": t1},
-			v2:       map[string]interface{}{"t": t1.Add(time.Nanosecond)},
+			name:     "truncatedates",
+			v1:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(900 * time.Nanosecond)},
+			v2:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(100 * time.Nanosecond)},
 			options:  []ContainsOption{EmptyMapValuesMatchAny(), ParseDates(time.Microsecond, true)},
 			expected: true,
 		},
 		{
-			name:     "rounddoesnttruncatedates",
+			name:     "rounddates",
 			v1:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(900 * time.Nanosecond)},
 			v2:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(100 * time.Nanosecond)},
-			options:  []ContainsOption{EmptyMapValuesMatchAny(), ParseDates(time.Microsecond, true)},
+			options:  []ContainsOption{EmptyMapValuesMatchAny(), RoundDates(time.Microsecond, true)},
 			expected: false,
 		},
 		{
-			name:     "truncatedates",
+			name:     "rounddates",
 			v1:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(900 * time.Nanosecond)},
-			v2:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(100 * time.Nanosecond)},
-			options:  []ContainsOption{EmptyMapValuesMatchAny(), TruncateDates(time.Microsecond, true)},
+			v2:       map[string]interface{}{"t": t1.Truncate(time.Microsecond).Add(700 * time.Nanosecond)},
+			options:  []ContainsOption{EmptyMapValuesMatchAny(), RoundDates(time.Microsecond, true)},
 			expected: true,
 		},
 		{