diff --git a/internal/commands/worklog.go b/internal/commands/worklog.go
index fa51328..a608fc6 100644
--- a/internal/commands/worklog.go
+++ b/internal/commands/worklog.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"time"
 
 	"git.hangman-lab.top/zhi/HarborForge.Cli/internal/output"
 )
@@ -35,9 +36,18 @@ func RunWorklogAdd(taskCode string, hours float64, desc, date, tokenFlag string)
 	if desc != "" {
 		payload["description"] = desc
 	}
+	// logged_date is a REQUIRED datetime on the backend. Default to now; if
+	// the operator passed --date <yyyy-mm-dd>, anchor it to start-of-day so a
+	// bare date still parses as a datetime.
+	loggedDate := time.Now().UTC().Format(time.RFC3339)
 	if date != "" {
-		payload["logged_date"] = date
+		if len(date) == 10 { // bare YYYY-MM-DD
+			loggedDate = date + "T00:00:00Z"
+		} else {
+			loggedDate = date
+		}
 	}
+	payload["logged_date"] = loggedDate
 
 	body, err := json.Marshal(payload)
 	if err != nil {