diff --git a/cmd/milestones/status.go b/cmd/milestones/status.go
index ce075e6..0166171 100644
--- a/cmd/milestones/status.go
+++ b/cmd/milestones/status.go
@@ -68,7 +68,7 @@ func StatusCmd() *cobra.Command {
 
 			ui.PrintSuccess(ui.EmojiMilestone, fmt.Sprintf("Active Milestone: %s", ui.Bold(activeMilestone.Name)))
 			ui.PrintInfo(4, "Project", projectName)
-			ui.PrintInfo(4, "Started", settings.FormatTime(activeMilestone.StartTime))
+			ui.PrintInfo(4, "Started", settings.FormatDateTime(activeMilestone.StartTime))
 			ui.PrintInfo(4, "Duration", ui.FormatDuration(activeMilestone.Duration()))
 			ui.PrintInfo(4, "Entries", fmt.Sprintf("%d", len(entries)))
 			ui.PrintInfo(4, "Total Time", ui.FormatDuration(totalTime))
diff --git a/internal/settings/global_config.go b/internal/settings/global_config.go
index ed364d5..0b37952 100644
--- a/internal/settings/global_config.go
+++ b/internal/settings/global_config.go
@@ -28,6 +28,9 @@ func DefaultGlobalConfig() *GlobalConfig {
 	}
 }
 
+// GetGlobalConfigPath returns the path to the global config file. If
+// the TMPO_DEV environment variable is set to 1 or true, a
+// developer-specific config path is returned.
 func GetGlobalConfigPath() (string, error) {
 	home, err := os.UserHomeDir()
 	if err != nil {
@@ -42,6 +45,8 @@ func GetGlobalConfigPath() (string, error) {
 	return filepath.Join(tmpoDir, "config.yaml"), nil
 }
 
+// LoadGlobalConfig loads the global config from disk. If the config
+// file does not exist the default config is returned.
 func LoadGlobalConfig() (*GlobalConfig, error) {
 	configPath, err := GetGlobalConfigPath()
 	if err != nil {
@@ -69,6 +74,8 @@ func LoadGlobalConfig() (*GlobalConfig, error) {
 	return &config, nil
 }
 
+// Save writes the GlobalConfig to the config file, creating the
+// config directory if necessary.
 func (gc *GlobalConfig) Save() error {
 	configPath, err := GetGlobalConfigPath()
 	if err != nil {
@@ -92,7 +99,8 @@ func (gc *GlobalConfig) Save() error {
 	return nil
 }
 
-// GetDisplayTimezone returns the user's configured timezone or local timezone as fallback
+// GetDisplayTimezone returns the user's configured timezone or the
+// local timezone as a fallback.
 func GetDisplayTimezone() *time.Location {
 	cfg, err := LoadGlobalConfig()
 	if err != nil || cfg.Timezone == "" {
@@ -107,11 +115,14 @@ func GetDisplayTimezone() *time.Location {
 	return loc
 }
 
-// ToDisplayTime converts a UTC time to the user's display timezone
+// ToDisplayTime converts the provided time to the user's display
+// timezone.
 func ToDisplayTime(t time.Time) time.Time {
 	return t.In(GetDisplayTimezone())
 }
 
+// FormatTime formats t according to the user's configured time
+// format. Falls back to 12-hour format "3:04 PM".
 func FormatTime(t time.Time) string {
 	t = ToDisplayTime(t)
 
@@ -127,6 +138,8 @@ func FormatTime(t time.Time) string {
 	return t.Format("3:04 PM")
 }
 
+// FormatTimePadded formats t with a padded hour for 12-hour formats
+// ("03:04 PM") or returns the 24-hour format when configured.
 func FormatTimePadded(t time.Time) string {
 	t = ToDisplayTime(t)
 
@@ -142,6 +155,8 @@ func FormatTimePadded(t time.Time) string {
 	return t.Format("03:04 PM")
 }
 
+// FormatDate formats t according to the user's configured date
+// format. Defaults to "01/02/2006" (MM/DD/YYYY).
 func FormatDate(t time.Time) string {
 	t = ToDisplayTime(t)
 
@@ -162,6 +177,7 @@ func FormatDate(t time.Time) string {
 	}
 }
 
+// FormatDateDashed formats t using dashes between date components.
 func FormatDateDashed(t time.Time) string {
 	t = ToDisplayTime(t)
 
@@ -182,20 +198,28 @@ func FormatDateDashed(t time.Time) string {
 	}
 }
 
+// FormatDateTime returns the date and time formatted according to
+// user preferences.
 func FormatDateTime(t time.Time) string {
 	return FormatDate(t) + " " + FormatTime(t)
 }
 
+// FormatDateTimeDashed returns the dashed date and time formatted
+// according to user preferences.
 func FormatDateTimeDashed(t time.Time) string {
 	return FormatDateDashed(t) + " " + FormatTime(t)
 }
 
+// FormatDateLong returns a long human-readable date string like
+// "Mon, Jan 2, 2006".
 func FormatDateLong(t time.Time) string {
 	t = ToDisplayTime(t)
 
 	return t.Format("Mon, Jan 2, 2006")
 }
 
+// FormatDateTimeLong returns a long human-readable date/time string
+// honoring the user's time format preference.
 func FormatDateTimeLong(t time.Time) string {
 	t = ToDisplayTime(t)
 
diff --git a/internal/ui/ui.go b/internal/ui/ui.go
index f3f89fe..a55791e 100644
--- a/internal/ui/ui.go
+++ b/internal/ui/ui.go
@@ -160,11 +160,15 @@ func FormatFileSize(bytes int64) string {
 }
 
 func FormatDuration(d time.Duration) string {
-	hours := int(d.Hours())
-	minutes := int(d.Minutes()) % 60
-	seconds := int(d.Seconds()) % 60
-
-	if hours > 0 {
+	totalSeconds := int(d.Seconds())
+	days := totalSeconds / 86400
+	hours := (totalSeconds % 86400) / 3600
+	minutes := (totalSeconds % 3600) / 60
+	seconds := totalSeconds % 60
+
+	if days > 0 {
+		return fmt.Sprintf("%dd %dh %dm %ds", days, hours, minutes, seconds)
+	} else if hours > 0 {
 		return fmt.Sprintf("%dh %dm %ds", hours, minutes, seconds)
 	} else if minutes > 0 {
 		return fmt.Sprintf("%dm %ds", minutes, seconds)
diff --git a/internal/ui/ui_test.go b/internal/ui/ui_test.go
index d902fec..87be392 100644
--- a/internal/ui/ui_test.go
+++ b/internal/ui/ui_test.go
@@ -206,9 +206,19 @@ func TestFormatDuration(t *testing.T) {
 			expected: "1s",
 		},
 		{
-			name:     "large duration",
+			name:     "large duration under 24h",
+			duration: 23*time.Hour + 45*time.Minute + 30*time.Second,
+			expected: "23h 45m 30s",
+		},
+		{
+			name:     "duration over 24h shows days",
 			duration: 25*time.Hour + 45*time.Minute + 30*time.Second,
-			expected: "25h 45m 30s",
+			expected: "1d 1h 45m 30s",
+		},
+		{
+			name:     "multi-day duration",
+			duration: 688*time.Hour + 30*time.Minute + 39*time.Second,
+			expected: "28d 16h 30m 39s",
 		},
 	}