fix(logs): resolve time ranges using client local time zone for logs commands

internal/cli/logs/logs.go

@@ -31,8 +31,8 @@ func Flags(options *Options) *pflag.FlagSet {
 			"Examples:\n"+
 			"  --since 2m30s                      Relative duration (2 minutes 30 seconds ago)\n"+
 			"  --since 1h                         Relative duration (1 hour ago)\n"+
-			"  --since 2025-11-24                 RFC 3339 date only (midnight using local timezone)\n"+
-			"  --since 2024-05-14T22:50:00        RFC 3339 date/time using local timezone\n"+
+			"  --since 2025-11-24                 RFC 3339 date only (midnight using client local timezone)\n"+
+			"  --since 2024-05-14T22:50:00        RFC 3339 date/time using client local timezone\n"+
 			"  --since 2024-01-31T10:30:00Z       RFC 3339 date/time in UTC\n"+
 			"  --since 1763953966                 Unix timestamp (seconds since January 1, 1970)")
 	set.StringVarP(&options.Tail, "tail", "n", "100",

internal/cli/logs/time.go

@@ -0,0 +1,72 @@
+package logs
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// TimeRange resolves log filters that could be RFC 3339, timestamp, or relative duration to UTC timestamps.
+// Dates without a timezone use now's location. Relative durations are computed from now.
+func TimeRange(since, until string, now time.Time) (string, string, error) {
+	var err error
+	since, err = timestamp(since, now)
+	if err != nil {
+		return "", "", fmt.Errorf("invalid --since value: %w", err)
+	}
+	until, err = timestamp(until, now)
+	if err != nil {
+		return "", "", fmt.Errorf("invalid --until value: %w", err)
+	}
+
+	return since, until, nil
+}
+
+func timestamp(value string, now time.Time) (string, error) {
+	if value == "" {
+		return "", nil
+	}
+	// A bare zero is the Unix epoch, matching Docker's log filters.
+	if duration, err := time.ParseDuration(value); value != "0" && err == nil {
+		return now.Add(-duration).UTC().Format(time.RFC3339Nano), nil
+	}
+
+	// Keep Docker's supported date layouts, but use the location's offset at the requested date.
+	for _, layout := range []string{
+		time.RFC3339Nano,
+		"2006-01-02T15:04Z07:00",
+		"2006-01-02T15Z07:00",
+		"2006-01-02Z07:00",
+		"2006-01-02T15:04:05.999999999",
+		"2006-01-02T15:04",
+		"2006-01-02T15",
+		"2006-01-02",
+	} {
+		if t, err := time.ParseInLocation(layout, value, now.Location()); err == nil {
+			return t.UTC().Format(time.RFC3339Nano), nil
+		}
+	}
+
+	seconds, fraction, hasFraction := strings.Cut(value, ".")
+	sec, err := strconv.ParseInt(seconds, 10, 64)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse '%s' as a time or duration", value)
+	}
+
+	var nsec int64
+	if hasFraction {
+		if len(fraction) == 0 || len(fraction) > 9 || strings.ContainsAny(fraction, "+-") {
+			return "", fmt.Errorf("invalid Unix timestamp fraction in '%s'", value)
+		}
+		nsec, err = strconv.ParseInt(fraction+strings.Repeat("0", 9-len(fraction)), 10, 64)
+		if err != nil {
+			return "", fmt.Errorf("invalid Unix timestamp fraction in '%s': %w", value, err)
+		}
+	}
+	t := time.Unix(sec, nsec).UTC()
+	if t.Year() < 0 || t.Year() > 9999 {
+		return "", fmt.Errorf("Unix timestamp '%s' is outside the RFC 3339 date range", value)
+	}
+	return t.Format(time.RFC3339Nano), nil
+}

internal/cli/logs/time_test.go

@@ -0,0 +1,81 @@
+package logs
+
+import (
+	"testing"
+	"time"
+
+	timetypes "github.com/docker/docker/api/types/time"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTimeRange(t *testing.T) {
+	t.Parallel()
+
+	location, err := time.LoadLocation("Australia/Sydney")
+	require.NoError(t, err)
+	// January is daylight-saving time, but July timestamps must use the winter offset.
+	now := time.Date(2026, 1, 15, 12, 0, 0, 123456789, location)
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"", ""},
+		{"2026-07-01", "2026-06-30T14:00:00Z"},
+		{"2026-07-01T10", "2026-07-01T00:00:00Z"},
+		{"2026-07-01T10:30", "2026-07-01T00:30:00Z"},
+		{"2026-07-01T10:30:45.123456789", "2026-07-01T00:30:45.123456789Z"},
+		{"2026-01-01T10:00:00", "2025-12-31T23:00:00Z"},
+		{"2026-07-01T10:30:45Z", "2026-07-01T10:30:45Z"},
+		{"2026-07-01T10:30:45+02:00", "2026-07-01T08:30:45Z"},
+		{"2026-07-01T10:30:45-04:00", "2026-07-01T14:30:45Z"},
+		{"2026-07-01T10+02:00", "2026-07-01T08:00:00Z"},
+		{"2026-07-01T10:30+02:00", "2026-07-01T08:30:00Z"},
+		{"2026-07-01+02:00", "2026-06-30T22:00:00Z"},
+		{"1763953966", "2025-11-24T03:12:46Z"},
+		{"1763953966.000000001", "2025-11-24T03:12:46.000000001Z"},
+		{"0", "1970-01-01T00:00:00Z"},
+		{"2m30s", "2026-01-15T00:57:30.123456789Z"},
+		{"-1h", "2026-01-15T02:00:00.123456789Z"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			since, until, err := TimeRange(tt.input, tt.input, now)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, since)
+			assert.Equal(t, tt.want, until)
+
+			if since != "" {
+				// The server-side Docker SDK must preserve the cutoff even in another timezone.
+				actual, err := timetypes.GetTimestamp(since, now.In(time.UTC))
+				require.NoError(t, err)
+				expected, err := time.Parse(time.RFC3339Nano, tt.want)
+				require.NoError(t, err)
+				sec, nsec, err := timetypes.ParseTimestamps(actual, 0)
+				require.NoError(t, err)
+				assert.True(t, expected.Equal(time.Unix(sec, nsec)))
+			}
+		})
+	}
+
+	since, until, err := TimeRange("3h", "1h30m", now)
+	require.NoError(t, err)
+	assert.Equal(t, "2026-01-14T22:00:00.123456789Z", since)
+	assert.Equal(t, "2026-01-14T23:30:00.123456789Z", until)
+}
+
+func TestTimeRange_Invalid(t *testing.T) {
+	t.Parallel()
+
+	for _, input := range []string{
+		"invalid", "2026-02-30", "2026-01-01T25:00:00", "1763953966.xyz",
+		"1763953966.1234567890", "253402300800",
+	} {
+		t.Run(input, func(t *testing.T) {
+			_, _, err := TimeRange(input, "", time.Now())
+			require.ErrorContains(t, err, "invalid --since value")
+			_, _, err = TimeRange("", input, time.Now())
+			require.ErrorContains(t, err, "invalid --until value")
+		})
+	}
+}