Let the blogger set a post's date, when writing it and afterwards

The post date is posts.created_at: it already drives ordering, the
archive, the feed and the displayed dates, so making it editable is a
form field rather than a new column. The datetime-local input degrades
to a text box on old browsers, so the server also accepts the value
typed by hand; blank keeps the current date.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

7 files changed, 61 insertions, 7 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 97798dc..09d9b7d 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -218,6 +218,13 @@ internal/web/         server.go (host router, middleware, render helpers)
   Adding a language: an entry in `i18n.languages`, a catalog file, a month
   table in `monthTables` (nominative, in-date and short forms), and the test
   gets a copy per language if its rules differ.
+- **Post date** is `posts.created_at` — there is no separate "published
+  at": the blogger sets it on the post form (`posted_at`, a
+  `datetime-local` input that degrades to a text box; `parsePostDate`
+  accepts `YYYY-MM-DD[THH:MM]`), for new and existing posts alike, and it
+  drives ordering, the archive, the feed and the displayed dates. Blank keeps
+  the current value; a new post starts at now. Times are in the server's
+  zone, which is also the one dates are rendered in.
 - **Slugs**: auto-generated from the title; on collision generated slugs
   get `-2`, `-3`…, user-typed slugs return a 409 with a message.
 - **Errors**: `store.ErrNotFound` / `store.ErrConflict` are the sentinels
diff --git a/internal/i18n/el.go b/internal/i18n/el.go
index 55b6cf6..eaaab5f 100644
--- a/internal/i18n/el.go
+++ b/internal/i18n/el.go
@@ -92,6 +92,7 @@ var el = map[string]string{
 	"Slug may only contain lowercase letters, digits and dashes.":             "Η διεύθυνση επιτρέπει μόνο πεζά λατινικά γράμματα, ψηφία και παύλες.",
 	"Pick a page for this post.":                                              "Επιλέξτε σελίδα για τη δημοσίευση.",
 	"Post is too long (200 KB max).":                                          "Η δημοσίευση είναι πολύ μεγάλη (έως 200 KB).",
+	"Enter the date as YYYY-MM-DD HH:MM.":                                     "Γράψτε την ημερομηνία ως ΕΕΕΕ-ΜΜ-ΗΗ ΩΩ:ΛΛ.",
 	"A post with that slug already exists on this page; choose another slug.": "Υπάρχει ήδη δημοσίευση με αυτή τη διεύθυνση στη σελίδα· διαλέξτε άλλη.",
 	"Saved. Refresh your blog to see it.":                                     "Αποθηκεύτηκε. Ανανεώστε το ιστολόγιό σας για να το δείτε.",
 	"Image not added:":                                                        "Η εικόνα δεν προστέθηκε:",
diff --git a/internal/store/posts.go b/internal/store/posts.go
index 94bc856..569640b 100644
--- a/internal/store/posts.go
+++ b/internal/store/posts.go
@@ -108,10 +108,15 @@ func (bs *BlogStore) PublishedPostBySlug(ctx context.Context, pageID int64, slug
 		WHERE p.page_id=$1 AND p.slug=$2 AND p.published`, pageID, slug))
 }
 
+// CreatePost inserts the post; a zero CreatedAt means now. The post date is
+// the blogger's to choose, so it is a plain column rather than a fixed stamp.
 func (bs *BlogStore) CreatePost(ctx context.Context, p *Post) (*Post, error) {
+	if p.CreatedAt.IsZero() {
+		p.CreatedAt = time.Now()
+	}
 	var id int64
-	err := bs.db.QueryRow(ctx, `INSERT INTO posts (page_id, slug, title, body_md, body_html, published) VALUES ($1,$2,$3,$4,$5,$6) RETURNING id`,
-		p.PageID, p.Slug, p.Title, p.BodyMD, p.BodyHTML, p.Published).Scan(&id)
+	err := bs.db.QueryRow(ctx, `INSERT INTO posts (page_id, slug, title, body_md, body_html, published, created_at) VALUES ($1,$2,$3,$4,$5,$6,$7) RETURNING id`,
+		p.PageID, p.Slug, p.Title, p.BodyMD, p.BodyHTML, p.Published, p.CreatedAt).Scan(&id)
 	if err != nil {
 		return nil, wrap(err)
 	}
@@ -119,8 +124,8 @@ func (bs *BlogStore) CreatePost(ctx context.Context, p *Post) (*Post, error) {
 }
 
 func (bs *BlogStore) UpdatePost(ctx context.Context, p *Post) error {
-	_, err := bs.db.Exec(ctx, `UPDATE posts SET page_id=$2, slug=$3, title=$4, body_md=$5, body_html=$6, published=$7, updated_at=now() WHERE id=$1`,
-		p.ID, p.PageID, p.Slug, p.Title, p.BodyMD, p.BodyHTML, p.Published)
+	_, err := bs.db.Exec(ctx, `UPDATE posts SET page_id=$2, slug=$3, title=$4, body_md=$5, body_html=$6, published=$7, created_at=$8, updated_at=now() WHERE id=$1`,
+		p.ID, p.PageID, p.Slug, p.Title, p.BodyMD, p.BodyHTML, p.Published, p.CreatedAt)
 	return wrap(err)
 }
 
diff --git a/internal/web/handlers_posts.go b/internal/web/handlers_posts.go
index 88d5c20..8327912 100644
--- a/internal/web/handlers_posts.go
+++ b/internal/web/handlers_posts.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/gramanas/blogspace/internal/markdown"
 	"github.com/gramanas/blogspace/internal/slug"
@@ -46,7 +47,7 @@ func (s *Server) handlePostForm(w http.ResponseWriter, r *http.Request) {
 		s.serverError(w, err)
 		return
 	}
-	p := &store.Post{Published: true}
+	p := &store.Post{Published: true, CreatedAt: time.Now()}
 	if r.PathValue("id") != "" {
 		if p = s.loadPost(w, r); p == nil {
 			return
@@ -66,7 +67,7 @@ func (s *Server) handlePostSave(w http.ResponseWriter, r *http.Request) {
 		s.serverError(w, err)
 		return
 	}
-	p := &store.Post{}
+	p := &store.Post{CreatedAt: time.Now()}
 	if r.PathValue("id") != "" {
 		if p = s.loadPost(w, r); p == nil {
 			return
@@ -84,6 +85,13 @@ func (s *Server) handlePostSave(w http.ResponseWriter, r *http.Request) {
 	fail := func(status int, msg string) {
 		s.renderStatus(w, r, status, "dashboard/post_form.html", map[string]any{"post": p, "pages": pages, "error": msg})
 	}
+	if at := strings.TrimSpace(r.FormValue("posted_at")); at != "" { // blank keeps the current date
+		var ok bool
+		if p.CreatedAt, ok = parsePostDate(at); !ok {
+			fail(http.StatusBadRequest, s.tr(r, "Enter the date as YYYY-MM-DD HH:MM."))
+			return
+		}
+	}
 	img, err := s.readUpload(r, "inline_image")
 	if err != nil {
 		fail(http.StatusBadRequest, s.tr(r, "Image not added:")+" "+err.Error())
@@ -137,6 +145,19 @@ func (s *Server) handlePostSave(w http.ResponseWriter, r *http.Request) {
 	redirectOK(w, r, "/b/"+blog.Subdomain+"/posts/"+strconv.FormatInt(p.ID, 10)+"/edit", s.tr(r, "Saved. Refresh your blog to see it."))
 }
 
+// parsePostDate reads the post form's date: what a datetime-local input sends,
+// or the same typed by hand where the browser shows a plain text box. The time
+// of day is optional. Times are taken in the server's zone, which is also the
+// zone the blog displays them in.
+func parsePostDate(v string) (time.Time, bool) {
+	for _, layout := range []string{"2006-01-02T15:04", "2006-01-02 15:04", "2006-01-02T15:04:05", "2006-01-02"} {
+		if t, err := time.ParseInLocation(layout, v, time.Local); err == nil {
+			return t, true
+		}
+	}
+	return time.Time{}, false
+}
+
 func (s *Server) handlePostDeleteConfirm(w http.ResponseWriter, r *http.Request) {
 	p := s.loadPost(w, r)
 	if p == nil {
diff --git a/internal/web/static/dashboard.css b/internal/web/static/dashboard.css
index 7a66ba5..5c766e7 100644
--- a/internal/web/static/dashboard.css
+++ b/internal/web/static/dashboard.css
@@ -59,7 +59,7 @@ p { margin: 0.6em 0; }
 label { display: block; margin: 0.8em 0; font-family: "IBM Plex Mono", "SF Mono", Menlo, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.8em; text-transform: uppercase; letter-spacing: 0.05em; }
 label .muted { text-transform: none; letter-spacing: 0; }
 label code { text-transform: none; letter-spacing: 0; }
-input[type=text], input[type=password], input[type=number], input:not([type]), input[type=file], select, textarea {
+input[type=text], input[type=password], input[type=number], input[type=datetime-local], input:not([type]), input[type=file], select, textarea {
   width: 100%; max-width: 100%; padding: 0.5em 0.6em; margin-top: 0.25em; border: 2px solid #1d1a17; font: inherit; font-family: -apple-system, "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 16px; text-transform: none; letter-spacing: 0; background: #fffdf8; color: #1d1a17; }
 input:focus, select:focus, textarea:focus, button:focus, .btn:focus { outline: 2px solid #c8541a; outline-offset: 1px; }
 input[type=color] { width: 4em; height: 2.3em; padding: 0.1em; margin-top: 0.25em; border: 2px solid #1d1a17; background: #fffdf8; }
diff --git a/internal/web/templates/dashboard/post_form.html b/internal/web/templates/dashboard/post_form.html
index af48215..8069a9a 100644
--- a/internal/web/templates/dashboard/post_form.html
+++ b/internal/web/templates/dashboard/post_form.html
@@ -11,6 +11,8 @@
       </label>
       <label>{{t "Address"}} <span class="muted">({{t "optional, made from the title"}})</span><br>
         <input name="slug" value="{{.Data.post.Slug}}" pattern="[a-z0-9]([a-z0-9-]*[a-z0-9])?" maxlength="80"></label>
+      <label>{{t "Date"}}<br>
+        <input type="datetime-local" name="posted_at" value="{{.Data.post.CreatedAt.Format "2006-01-02T15:04"}}" placeholder="YYYY-MM-DD HH:MM"></label>
     </div>
     <label for="ed-body">{{t "Content"}} <span class="muted">(Markdown)</span></label>
     {{template "editor" (dict "name" "body" "value" .Data.post.BodyMD "rows" 24 "tall" true "upload" (print "/b/" .Blog.Subdomain "/images/upload") "csrf" .CSRF)}}
diff --git a/internal/web/web_test.go b/internal/web/web_test.go
index ae26029..d7de43a 100644
--- a/internal/web/web_test.go
+++ b/internal/web/web_test.go
@@ -220,6 +220,24 @@ func TestValidLinkURL(t *testing.T) {
 	}
 }
 
+func TestParsePostDate(t *testing.T) {
+	for in, want := range map[string]time.Time{
+		"2026-09-14T08:30":    time.Date(2026, 9, 14, 8, 30, 0, 0, time.Local),
+		"2026-09-14 08:30":    time.Date(2026, 9, 14, 8, 30, 0, 0, time.Local),
+		"2026-09-14T08:30:15": time.Date(2026, 9, 14, 8, 30, 15, 0, time.Local),
+		"2026-09-14":          time.Date(2026, 9, 14, 0, 0, 0, 0, time.Local),
+	} {
+		if got, ok := parsePostDate(in); !ok || !got.Equal(want) {
+			t.Errorf("%q: got %v %v, want %v", in, got, ok, want)
+		}
+	}
+	for _, bad := range []string{"", "14/09/2026", "2026-13-01", "yesterday", "2026-09-14T25:00"} {
+		if _, ok := parsePostDate(bad); ok {
+			t.Errorf("%q should be rejected", bad)
+		}
+	}
+}
+
 func TestGroupArchive(t *testing.T) {
 	d := func(y int, m time.Month, day int) time.Time { return time.Date(y, m, day, 12, 0, 0, 0, time.UTC) }
 	posts := []store.PostRef{{Title: "d", CreatedAt: d(2026, 9, 3)}, {Title: "c", CreatedAt: d(2026, 9, 1)}, {Title: "b", CreatedAt: d(2026, 2, 1)}, {Title: "a", CreatedAt: d(2025, 12, 31)}}