feat: specify date for add command

README.md

@@ -177,6 +177,12 @@ cospend add "Hotel" 150.00 -p vacation -m "credit card" -o "2 nights"
 
 # Add an expense in a different currency
 cospend add "Souvenirs" 30.00 -p vacation -C usd
+
+# Add an expense with a specific date
+cospend add "Lunch" 15.00 -p myproject -d 2026-03-15
+cospend add "Lunch" 15.00 -p myproject -d 03-15        # assumes current year
+cospend add "Lunch" 15.00 -p myproject -d -1d          # yesterday
+cospend add "Lunch" 15.00 -p myproject -d +2d          # 2 days from now
 ```
 
 #### Add Command Flags
@@ -190,6 +196,7 @@ cospend add "Souvenirs" 30.00 -p vacation -C usd
 | `-C`  | `--convert`  | Currency to convert to (by ID, name, or code like `usd`)  |
 | `-m`  | `--method`   | Payment method by ID or case-insensitive name             |
 | `-o`  | `--comment`  | Additional details about the bill                         |
+| `-d`  | `--date`     | Date of expense (`YYYY-MM-DD`, `MM-DD`, or relative like `-1d`, `+2w`) |
 | `-h`  | `--help`     | Display help information                                  |
 
 ---

cmd/add.go

@@ -20,6 +20,7 @@ var (
 	convertTo     string
 	paymentMethod string
 	comment       string
+	addDate       string
 )
 
 // NewAddCommand creates the add command
@@ -42,6 +43,7 @@ Examples:
 	cmd.Flags().StringVarP(&convertTo, "convert", "C", "", "Currency to convert to")
 	cmd.Flags().StringVarP(&paymentMethod, "method", "m", "", "Payment method by ID or name")
 	cmd.Flags().StringVarP(&comment, "comment", "o", "", "Additional details about the bill")
+	cmd.Flags().StringVarP(&addDate, "date", "d", "", "Date of expense (YYYY-MM-DD, MM-DD, or relative like -1d, +2w)")
 
 	return cmd
 }
@@ -118,13 +120,23 @@ func runAdd(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	// Resolve date
+	billDate := time.Now().Format("2006-01-02")
+	if addDate != "" {
+		parsed, err := parseDate(addDate)
+		if err != nil {
+			return err
+		}
+		billDate = parsed
+	}
+
 	// Build bill
 	bill := api.Bill{
 		What:    expenseName,
 		Amount:  amount,
 		PayerID: payerID,
 		OwedTo:  owedIDs,
-		Date:    time.Now().Format("2006-01-02"),
+		Date:    billDate,
 	}
 
 	// Resolve optional category
@@ -215,5 +227,45 @@ func runAdd(cmd *cobra.Command, args []string) error {
 	if bill.Comment != "" {
 		_, _ = fmt.Fprintf(out, "  Comment:  %s\n", bill.Comment)
 	}
+	if addDate != "" {
+		_, _ = fmt.Fprintf(out, "  Date:     %s\n", bill.Date)
+	}
 	return nil
 }
+
+func parseDate(s string) (string, error) {
+	s = strings.TrimSpace(s)
+
+	// Try relative date: -1d, +2d, -1w, +2w, -1m, +2m
+	if len(s) >= 2 && (s[0] == '+' || s[0] == '-') {
+		unit := s[len(s)-1]
+		valueStr := s[1 : len(s)-1]
+		value, err := strconv.Atoi(valueStr)
+		if err == nil {
+			if s[0] == '-' {
+				value = -value
+			}
+			now := time.Now()
+			switch unit {
+			case 'd':
+				return now.AddDate(0, 0, value).Format("2006-01-02"), nil
+			case 'w':
+				return now.AddDate(0, 0, value*7).Format("2006-01-02"), nil
+			case 'm':
+				return now.AddDate(0, value, 0).Format("2006-01-02"), nil
+			}
+		}
+	}
+
+	// Try full date YYYY-MM-DD
+	if _, err := time.Parse("2006-01-02", s); err == nil {
+		return s, nil
+	}
+
+	// Try short date MM-DD (assume current year)
+	if t, err := time.Parse("01-02", s); err == nil {
+		return fmt.Sprintf("%d-%s", time.Now().Year(), t.Format("01-02")), nil
+	}
+
+	return "", fmt.Errorf("invalid date: %s (expected YYYY-MM-DD, MM-DD, or relative like -1d, +2w)", s)
+}

cmd/add_test.go

@@ -3,9 +3,11 @@ package cmd
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"testing"
+	"time"
 
 	"github.com/chenasraf/cospend-cli/internal/api"
 )
@@ -41,6 +43,7 @@ func resetFlags() {
 	convertTo = ""
 	paymentMethod = ""
 	comment = ""
+	addDate = ""
 	infoCached = false
 }
 
@@ -72,7 +75,7 @@ func TestNewAddCommand(t *testing.T) {
 	}
 
 	// Check flags exist (project is now a persistent flag on root)
-	flags := []string{"category", "by", "for", "convert", "method", "comment"}
+	flags := []string{"category", "by", "for", "convert", "method", "comment", "date"}
 	for _, flag := range flags {
 		if cmd.Flags().Lookup(flag) == nil {
 			t.Errorf("Missing flag: %s", flag)
@@ -87,6 +90,7 @@ func TestNewAddCommand(t *testing.T) {
 		"C": "convert",
 		"m": "method",
 		"o": "comment",
+		"d": "date",
 	}
 	for short, long := range shortFlags {
 		flag := cmd.Flags().ShorthandLookup(short)
@@ -484,3 +488,92 @@ func TestAddCommandAPIError(t *testing.T) {
 		t.Error("Expected error from API")
 	}
 }
+
+func TestParseDate(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		wantDate string
+		wantErr  bool
+	}{
+		{"full date", "2026-03-15", "2026-03-15", false},
+		{"short date", "03-15", fmt.Sprintf("%d-03-15", time.Now().Year()), false},
+		{"with spaces", " 2026-01-01 ", "2026-01-01", false},
+		{"relative -1d", "-1d", time.Now().AddDate(0, 0, -1).Format("2006-01-02"), false},
+		{"relative +2d", "+2d", time.Now().AddDate(0, 0, 2).Format("2006-01-02"), false},
+		{"relative -1w", "-1w", time.Now().AddDate(0, 0, -7).Format("2006-01-02"), false},
+		{"relative +2w", "+2w", time.Now().AddDate(0, 0, 14).Format("2006-01-02"), false},
+		{"relative -1m", "-1m", time.Now().AddDate(0, -1, 0).Format("2006-01-02"), false},
+		{"relative +3m", "+3m", time.Now().AddDate(0, 3, 0).Format("2006-01-02"), false},
+		{"invalid", "not-a-date", "", true},
+		{"invalid short", "13-40", "", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := parseDate(tt.input)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("parseDate() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !tt.wantErr && got != tt.wantDate {
+				t.Errorf("parseDate() = %v, want %v", got, tt.wantDate)
+			}
+		})
+	}
+}
+
+func TestAddCommandWithDate(t *testing.T) {
+	project := api.Project{
+		ID:   "test-project",
+		Name: "Test Project",
+		Members: []api.Member{
+			{ID: 1, Name: "testuser", UserID: "testuser"},
+		},
+	}
+
+	var receivedBill map[string]string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/ocs/v2.php/apps/cospend/api/v1/projects/test-project" {
+			_ = json.NewEncoder(w).Encode(makeOCSResponse(200, project))
+			return
+		}
+		if r.URL.Path == "/ocs/v2.php/cloud/user" {
+			_ = json.NewEncoder(w).Encode(makeOCSResponse(200, map[string]string{"locale": "en_US", "language": "en"}))
+			return
+		}
+		if r.URL.Path == "/ocs/v2.php/apps/cospend/api/v1/projects/test-project/bills" {
+			_ = r.ParseForm()
+			receivedBill = make(map[string]string)
+			for k, v := range r.Form {
+				if len(v) > 0 {
+					receivedBill[k] = v[0]
+				}
+			}
+			_ = json.NewEncoder(w).Encode(makeOCSResponse(200, map[string]int{"id": 1}))
+			return
+		}
+	}))
+	defer server.Close()
+
+	cleanup := setupTestEnv(t, server.URL)
+	defer cleanup()
+
+	ProjectID = "test-project"
+	cmd := NewAddCommand()
+	var stdout bytes.Buffer
+	cmd.SetOut(&stdout)
+	cmd.SetArgs([]string{"Groceries", "25.50", "-d", "2026-06-15"})
+
+	err := cmd.Execute()
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	if receivedBill["date"] != "2026-06-15" {
+		t.Errorf("Wrong date: got %s, want 2026-06-15", receivedBill["date"])
+	}
+	if !bytes.Contains(stdout.Bytes(), []byte("Date:     2026-06-15")) {
+		t.Errorf("Output should show date, got:\n%s", stdout.String())
+	}
+}