diff --git a/git-quick-stats b/git-quick-stats
index 39b8d29..b1ebbcc 100755
--- a/git-quick-stats
+++ b/git-quick-stats
@@ -80,6 +80,56 @@ fi
 # Set the legacy theme by typing "export _MENU_THEME=legacy"
 _theme="${_MENU_THEME:=default}"
 
+# DESC: Shows a calendar heatmap of commits per day-of-week per month for a given author
+# ARGS: $author (required)
+function commitsCalendarByAuthor() {
+    local author="${1:-}"
+    [[ -z "$author" ]] && { echo "Usage: commitsCalendarByAuthor <author>"; return 1; }
+
+    optionPicked "Commit Activity Calendar for '$author'"
+
+    # Print header
+    printf "\n      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec\n"
+
+    # Gather commit counts
+    git -c log.showSignature=false log --use-mailmap $_merges \
+        --date=iso --author="$author" "$_since" "$_until" $_log_options \
+        --pretty='%ad' $_pathspec | awk '
+        {
+            split($0, a, " ");
+            # a[1] = YYYY-MM-DD
+            split(a[1], date_fields, "-");
+            mon = date_fields[2] + 0;
+            cmd = "date -d \"" a[1] "\" +%u";
+            cmd | getline weekday;
+            close(cmd);
+            # weekday: 1=Mon, ..., 7=Sun
+            count[weekday][mon]++;
+        }
+        END {
+            # Output matrix
+            for (d=1; d<=7; d++) {
+                if (d==1) printf "Mon   ";
+                else if (d==2) printf "Tue   ";
+                else if (d==3) printf "Wed   ";
+                else if (d==4) printf "Thu   ";
+                else if (d==5) printf "Fri   ";
+                else if (d==6) printf "Sat   ";
+                else if (d==7) printf "Sun   ";
+                for (m=1; m<=12; m++) {
+                    c = count[d][m]+0;
+                    if (c==0)       out="...";
+                    else if (c<=9)  out="░░░";
+                    else if (c<=19)  out="▒▒▒";
+                    else            out="▓▓▓";
+                    printf "%s%s", out, (m<12?" ":"\n");
+                }
+            }
+            printf "\nLegend: ... = 0   ░░░ = 1–9   ▒▒▒ = 10–19   ▓▓▓ = 20+ commits\n";
+        }
+    '
+}
+
 ################################################################################
 # HELPER AND MENU FUNCTIONS
 
@@ -281,6 +331,8 @@ function showMenu() {
     printf %b "${NUMS}   21)${TEXT} Git commits per timezone by author\\n"
     printf %b "\\n${TITLES} Suggest:\\n"
     printf %b "${NUMS}   22)${TEXT} Code reviewers (based on git history)\\n"
+    printf %b "\\n${TITLES} Calendar:\\n"
+    printf %b "${NUMS}   23)${TEXT} Activity calendar by author\\n"
     printf %b "\\n${HELP_TXT}Please enter a menu option or ${EXIT_TXT}press Enter to exit.\\n"
     printf %b "${TEXT}> ${NORMAL}"
     read -r opt
@@ -1134,6 +1186,13 @@ if [[ "$#" -eq 1 ]]; then
                 read -r -p "Which author? " author
             done
             commitsByTimezone "${author}";;
+        # ACTIVITY OPTIONS
+        -k|--commits-calendar-by-author)
+            author="${_GIT_AUTHOR:-}"
+            while [[ -z "${author}" ]]; do
+                read -r -p "Which author? " author
+            done
+            commitsCalendarByAuthor "${author}";;
         # SUGGEST OPTIONS
         -r|--suggest-reviewers) suggestReviewers;;
         -h|-\?|--help) usage;;
@@ -1220,6 +1279,11 @@ while [[ "${opt}" != "" ]]; do
            done
            commitsByTimezone "${author}"; showMenu;;
        22) suggestReviewers; showMenu;;
+       23) author=""
+            while [[ -z "${author}" ]]; do
+                read -r -p "Which author? " author
+            done
+            commitsCalendarByAuthor "${author}"; showMenu;;
        q|"\n") exit;;
        *) clear; optionPicked "Pick an option from the menu"; showMenu;;
     esac
diff --git a/git-quick-stats.1 b/git-quick-stats.1
index 76a6ca5..34dfb51 100644
--- a/git-quick-stats.1
+++ b/git-quick-stats.1
@@ -1,4 +1,4 @@
-.TH git-quick-stats "1" "April 2024" "git-quick-stats" "User Commands"
+.TH git-quick-stats "1" "June 2025" "git-quick-stats" "User Commands"
 .SH NAME
 .B git\-quick\-stats
 \- Simple and efficient way to access various stats in a git repository.
@@ -124,6 +124,11 @@ displays a list of commits per timezone
 .IP
 displays a list of commits per timezone by author
 .HP
+.PP
+\fB\-\-activity\-calendar\fR
+.IP
+displays a calendar-style grid of commit activity per day-of-week and month for a selected author.
+.HP
 .SH SUGGEST OPTIONS
 .PP
 \fB\-r\fR, \fB\-\-suggest\-reviewers\fR
@@ -168,8 +173,34 @@ You can set _GIT_BRANCH to set the branch of the stats, example:
 .PP
 .B  export _GIT_BRANCH="master"
 .PP
+.SH Calendar activity output
+.PP
+\fBactivity-calendar\fR outputs a visual grid of commit activity for a selected author, grouped by day-of-week (rows: Mon..Sun) and month (columns: Jan..Dec). Each cell is 3 characters wide, separated by one space.
+.PP
+Sample output:
+.PP
+.nf
+      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
+Mon   ▓▓▓ ░░░ ▒▒▒ ░░░ ░░░ ▒▒▒ ▓▓▓ ░░░ ░░░ ▓▓▓ ▒▒▒ ▒▒▒
+Tue   ▒▒▒ ░░░ ▒▒▒ ░░░ ▒▒▒ ░░░ ▒▒▒ ▓▓▓ ▒▒▒ ░░░ ░░░ ░░░
+Wed   ░░░ ▓▓▓ ░░░ ▓▓▓ ▒▒▒ ░░░ ░░░ ▒▒▒ ░░░ ░░░ ▓▓▓ ░░░
+Thu   ░░░ ▒▒▒ ░░░ ░░░ ▒▒▒ ░░░ ▓▓▓ ▒▒▒ ▒▒▒ ░░░ ░░░ ▒▒▒
+Fri   ▒▒▒ ░░░ ▒▒▒ ▓▓▓ ░░░ ▓▓▓ ▒▒▒ ░░░ ▒▒▒ ░░░ ▒▒▒ ░░░
+Sat   ░░░ ░░░ ▒▒▒ ░░░ ░░░ ░░░ ▒▒▒ ░░░ ▒▒▒ ▓▓▓ ▒▒▒ ░░░
+Sun   ▓▓▓ ░░░ ▓▓▓ ░░░ ░░░ ▓▓▓ ░░░ ▒▒▒ ░░░ ░░░ ▓▓▓ ░░░
+
+Legend: ... = 0   ░░░ = 1–2   ▒▒▒ = 3–5   ▓▓▓ = 6+ commits
+.PP
 You can set _GIT_IGNORE_AUTHORS to filter out specific authors, example:
 .PP
 .B  export _GIT_IGNORE_AUTHORS="(author@examle.com|username)"
 .
 .fi
+
+.PP
+.SH SEE ALSO
+.BR git (1)
+.PP
+Project homepage:
+.UR https://github.com/git-quick-stats/git-quick-stats
+.UE
\ No newline at end of file