diff --git a/internal/commands/checkins.go b/internal/commands/checkins.go
index 45a9c242f..266e5130c 100644
--- a/internal/commands/checkins.go
+++ b/internal/commands/checkins.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/basecamp/basecamp-sdk/go/pkg/basecamp"
 	"github.com/spf13/cobra"
@@ -13,6 +14,8 @@ import (
 	"github.com/basecamp/basecamp-cli/internal/richtext"
 )
 
+var checkinsNow = time.Now
+
 // NewCheckinsCmd creates the checkins command group.
 func NewCheckinsCmd() *cobra.Command {
 	var project string
@@ -774,6 +777,10 @@ func newCheckinsAnswerCreateCmd(project *string) *cobra.Command {
 			if err != nil {
 				return output.ErrUsage("Invalid question ID")
 			}
+			effectiveGroupOn := groupOn
+			if effectiveGroupOn == "" {
+				effectiveGroupOn = checkinsNow().Format("2006-01-02")
+			}
 
 			html := richtext.MarkdownToHTML(content)
 
@@ -794,7 +801,7 @@ func newCheckinsAnswerCreateCmd(project *string) *cobra.Command {
 
 			req := &basecamp.CreateAnswerRequest{
 				Content: html,
-				GroupOn: groupOn,
+				GroupOn: effectiveGroupOn,
 			}
 
 			answer, err := app.Account().Checkins().CreateAnswer(cmd.Context(), qID, req)
@@ -825,7 +832,7 @@ func newCheckinsAnswerCreateCmd(project *string) *cobra.Command {
 		},
 	}
 
-	cmd.Flags().StringVar(&groupOn, "date", "", "Date to group answer (ISO 8601, e.g., 2024-01-22)")
+	cmd.Flags().StringVar(&groupOn, "date", "", "Date to group answer (ISO 8601, e.g., 2024-01-22; defaults to today)")
 	cmd.Flags().StringArrayVar(&attachFiles, "attach", nil, "Attach file (repeatable)")
 
 	return cmd
diff --git a/internal/commands/checkins_test.go b/internal/commands/checkins_test.go
new file mode 100644
index 000000000..7194e7a22
--- /dev/null
+++ b/internal/commands/checkins_test.go
@@ -0,0 +1,103 @@
+package commands
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type mockCheckinsAnswerCreateTransport struct {
+	recordedPath string
+	recordedBody map[string]any
+}
+
+func (m *mockCheckinsAnswerCreateTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	header := make(http.Header)
+	header.Set("Content-Type", "application/json")
+
+	switch {
+	case req.Method == "GET" && strings.Contains(req.URL.Path, "/projects.json"):
+		return &http.Response{
+			StatusCode: 200,
+			Body:       io.NopCloser(strings.NewReader(`[{"id":123,"name":"Test Project"}]`)),
+			Header:     header,
+		}, nil
+	case req.Method == "POST" && strings.Contains(req.URL.Path, "/questions/456/answers.json"):
+		m.recordedPath = req.URL.Path
+		if req.Body != nil {
+			defer req.Body.Close()
+		}
+		body, err := io.ReadAll(req.Body)
+		if err != nil {
+			return nil, err
+		}
+		if err := json.Unmarshal(body, &m.recordedBody); err != nil {
+			return nil, err
+		}
+		return &http.Response{
+			StatusCode: 201,
+			Body: io.NopCloser(strings.NewReader(`{
+				"id": 789,
+				"content": "<p>hello world</p>",
+				"group_on": "2026-03-25",
+				"creator": {"name": "Rob Zolkos"},
+				"parent": {"id": 456, "title": "What did you work on today?", "type": "Question", "url": "https://example.test/questions/456", "app_url": "https://example.test/questions/456"},
+				"bucket": {"id": 123, "name": "Test Project", "type": "Project"},
+				"status": "active",
+				"type": "Question::Answer",
+				"title": "Answer"
+			}`)),
+			Header: header,
+		}, nil
+	default:
+		return &http.Response{
+			StatusCode: 404,
+			Body:       io.NopCloser(strings.NewReader(`{"error":"Not Found"}`)),
+			Header:     header,
+		}, nil
+	}
+}
+
+func TestCheckinsAnswerCreateDefaultsDateToToday(t *testing.T) {
+	originalNow := checkinsNow
+	checkinsNow = func() time.Time {
+		return time.Date(2026, 3, 25, 9, 30, 0, 0, time.Local)
+	}
+	t.Cleanup(func() {
+		checkinsNow = originalNow
+	})
+
+	transport := &mockCheckinsAnswerCreateTransport{}
+	app, _ := newTestAppWithTransport(t, transport)
+	app.Config.ProjectID = "123"
+
+	project := ""
+	cmd := newCheckinsAnswerCreateCmd(&project)
+
+	err := executeCommand(cmd, app, "456", "hello world")
+	require.NoError(t, err)
+	require.NotNil(t, transport.recordedBody)
+	assert.Equal(t, "/99999/questions/456/answers.json", transport.recordedPath)
+	assert.Equal(t, "<p>hello world</p>", transport.recordedBody["content"])
+	assert.Equal(t, "2026-03-25", transport.recordedBody["group_on"])
+}
+
+func TestCheckinsAnswerCreatePreservesExplicitDate(t *testing.T) {
+	transport := &mockCheckinsAnswerCreateTransport{}
+	app, _ := newTestAppWithTransport(t, transport)
+	app.Config.ProjectID = "123"
+
+	project := ""
+	cmd := newCheckinsAnswerCreateCmd(&project)
+
+	err := executeCommand(cmd, app, "456", "hello world", "--date", "2026-03-25")
+	require.NoError(t, err)
+	require.NotNil(t, transport.recordedBody)
+	assert.Equal(t, "2026-03-25", transport.recordedBody["group_on"])
+}
diff --git a/internal/tui/workspace/data/hub.go b/internal/tui/workspace/data/hub.go
index a9e9c7ff9..400b75afb 100644
--- a/internal/tui/workspace/data/hub.go
+++ b/internal/tui/workspace/data/hub.go
@@ -10,6 +10,8 @@ import (
 	"github.com/basecamp/basecamp-sdk/go/pkg/basecamp"
 )
 
+var hubNow = time.Now
+
 // Hub is the central data coordinator providing typed, realm-scoped pool access.
 //
 // Hub manages three realm tiers:
@@ -1160,7 +1162,10 @@ func (h *Hub) CreateCheckinAnswer(ctx context.Context, accountID string, project
 	if client == nil {
 		return fmt.Errorf("no client for account %s", accountID)
 	}
-	_, err := client.Checkins().CreateAnswer(ctx, questionID, &basecamp.CreateAnswerRequest{Content: content})
+	_, err := client.Checkins().CreateAnswer(ctx, questionID, &basecamp.CreateAnswerRequest{
+		Content: content,
+		GroupOn: hubNow().Format("2006-01-02"),
+	})
 	return err
 }
 
diff --git a/internal/tui/workspace/data/hub_test.go b/internal/tui/workspace/data/hub_test.go
index 778afba15..4ac752520 100644
--- a/internal/tui/workspace/data/hub_test.go
+++ b/internal/tui/workspace/data/hub_test.go
@@ -1,6 +1,11 @@
 package data
 
 import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"strings"
 	"testing"
 	"time"
 
@@ -9,6 +14,82 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+type hubCheckinsTestTokenProvider struct{}
+
+func (hubCheckinsTestTokenProvider) AccessToken(_ context.Context) (string, error) {
+	return "test-token", nil
+}
+
+type mockHubCheckinsTransport struct {
+	recordedPath string
+	recordedBody map[string]any
+}
+
+func (m *mockHubCheckinsTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	header := make(http.Header)
+	header.Set("Content-Type", "application/json")
+
+	switch {
+	case req.Method == http.MethodPost && strings.Contains(req.URL.Path, "/questions/456/answers.json"):
+		m.recordedPath = req.URL.Path
+		if req.Body != nil {
+			defer req.Body.Close()
+		}
+		body, err := io.ReadAll(req.Body)
+		if err != nil {
+			return nil, err
+		}
+		if err := json.Unmarshal(body, &m.recordedBody); err != nil {
+			return nil, err
+		}
+		return &http.Response{
+			StatusCode: http.StatusCreated,
+			Body: io.NopCloser(strings.NewReader(`{
+				"id": 789,
+				"content": "<p>hello world</p>",
+				"group_on": "2026-03-25",
+				"creator": {"name": "Rob Zolkos"},
+				"parent": {"id": 456, "title": "What did you work on today?", "type": "Question", "url": "https://example.test/questions/456", "app_url": "https://example.test/questions/456"},
+				"bucket": {"id": 123, "name": "Test Project", "type": "Project"},
+				"status": "active",
+				"type": "Question::Answer",
+				"title": "Answer"
+			}`)),
+			Header: header,
+		}, nil
+	default:
+		return &http.Response{
+			StatusCode: http.StatusNotFound,
+			Body:       io.NopCloser(strings.NewReader(`{"error":"Not Found"}`)),
+			Header:     header,
+		}, nil
+	}
+}
+
+func TestHubCreateCheckinAnswerDefaultsDateToToday(t *testing.T) {
+	originalNow := hubNow
+	hubNow = func() time.Time {
+		return time.Date(2026, 3, 25, 9, 30, 0, 0, time.Local)
+	}
+	t.Cleanup(func() {
+		hubNow = originalNow
+	})
+
+	transport := &mockHubCheckinsTransport{}
+	sdk := basecamp.NewClient(&basecamp.Config{}, hubCheckinsTestTokenProvider{},
+		basecamp.WithTransport(transport),
+		basecamp.WithMaxRetries(0),
+	)
+	h := NewHub(NewMultiStore(sdk), "")
+
+	err := h.CreateCheckinAnswer(context.Background(), "99999", 123, 456, "<p>hello world</p>")
+	require.NoError(t, err)
+	require.NotNil(t, transport.recordedBody)
+	assert.Equal(t, "/99999/questions/456/answers.json", transport.recordedPath)
+	assert.Equal(t, "<p>hello world</p>", transport.recordedBody["content"])
+	assert.Equal(t, "2026-03-25", transport.recordedBody["group_on"])
+}
+
 func TestHubNewHasGlobalRealm(t *testing.T) {
 	h := NewHub(nil, "")
 	require.NotNil(t, h.Global())
diff --git a/skills/basecamp/SKILL.md b/skills/basecamp/SKILL.md
index d4b131a52..a528df86c 100644
--- a/skills/basecamp/SKILL.md
+++ b/skills/basecamp/SKILL.md
@@ -533,7 +533,7 @@ basecamp checkins answers <question_id> --in <project>  # List answers
 basecamp checkins answer <id> --in <project>      # Answer details
 basecamp checkins question create "What did you work on?" --in <project>
 basecamp checkins question update <id> "New question" --frequency every_week
-basecamp checkins answer create <question-id> "My answer" --in <project>
+basecamp checkins answer create <question-id> "My answer" --in <project>  # Defaults to today
 basecamp checkins answer update <id> "Updated" --in <project>
 ```
 
@@ -758,6 +758,7 @@ cat ~/.config/basecamp/accounts.json              # Check available accounts
 - `basecamp comment <id> "Text"` (not a flag)
 - `basecamp webhooks create "https://..." --in <project>` (not `--url`)
 - `basecamp checkins answer create <question-id> "content"` (not `--question`)
+- `--date YYYY-MM-DD` is optional for `checkins answer create`; if omitted, it defaults to today
 
 **Missing argument errors (code: "usage"):**
 When a required positional argument is missing, the CLI returns a structured error naming