diff --git a/src/awk/update.awk b/src/awk/update.awk
new file mode 100644
index 0000000..3ac88bc
--- /dev/null
+++ b/src/awk/update.awk
@@ -0,0 +1,102 @@
+function getcontent(content_line, prop)
+{
+  return substr(content_line[prop], index(content_line[prop], ":") + 1);
+}
+
+function escape(str)
+{
+  gsub("\\\\", "\\\\", str);
+  gsub(";",  "\\\\;",    str);
+  gsub(",",  "\\\\,",    str);
+}
+
+function print_fold(nameparam, content,    i, s)
+{
+  i = 74 - length(nameparam);
+  s = substr(content, 1, i);
+  print nameparam s;
+  s = substr(content, i+1, 73);
+  i = i + 73;
+  while (s)
+  {
+    print " " s;
+    s = substr(content, i+1, 73);
+    i = i + 73;
+  }
+}
+
+BEGIN { 
+  FS=":";
+  zulu = strftime("%Y%m%dT%H%M%SZ", systime(), 1);
+}
+
+ENDFILE { 
+  if (NR == FNR)
+  {
+    # Sanitize input
+    cmd = "date +\"%R\""
+    cmd | getline now
+    close(cmd)
+    # if time is set to 00:00 or right now, assume it's a date
+    # and not a datetime entry.
+    from = from ? from : "now"
+    cmd = "date -d \"" from "\" +\"%R\"";
+    cmd | getline t
+    close(cmd)
+    if (t == "00:00" || t == now) {
+      from_type = "DATE"
+      cmd = "date -d \"" from "\" +\"%Y%m%d\"";
+    } else {
+      from_type = "DATE-TIME"
+      cmd = "date -d \"" from "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
+    }
+    cmd | getline from
+    close(cmd)
+    #
+    to = to ? to : "now"
+    cmd = "date -d \"" to "\" +\"%R\"";
+    cmd | getline t
+    close(cmd)
+    if (t == "00:00" || t == now) {
+      to_type = "DATE"
+      cmd = "date -d \"" to "\" +\"%Y%m%d\"";
+    } else {
+      to_type = "DATE-TIME"
+      cmd = "date -d \"" to "\" +\"@%s\" | xargs date -u +\"%Y%m%dT%H%M00Z\" -d"
+    }
+    cmd | getline to
+    close(cmd)
+  }
+  escape(summary);
+  escape(desc);
+}
+
+NR == FNR && desc { desc = desc "\\n" $0; next; }
+NR == FNR {
+  from = substr($0, 1, 6) == "::: |>" ? substr($0, 8) : "";
+  getline
+  to = substr($0, 1, 6) == "::: <|" ? substr($0, 8) : "";
+  getline
+  summary = substr($0, 1, 2) == "# " ? substr($0, 3) : ""
+  getline # This line should be empty
+  getline # First line of description
+  desc = $0;
+  next;
+}
+
+/^BEGIN:VEVENT$/                                              { inside = 1; print; next }
+/^X-ALT-DESC/ && inside                                       { next } # drop this alternative description
+/^ / && inside                                                { next } # drop this folded line (the only content with folded lines will be updated)
+/^(DTSTART|DTEND|SUMMARY|CATEGORIES|DESCRIPTION|LAST-MODIFIED)/ && inside { next } # skip for now, we will write updated fields at the end
+/^SEQUENCE/ && inside                                         { seq = $2; next } # store sequence number and skip
+/^END:VEVENT$/ {
+  seq = seq ? seq + 1 : 1
+  print "SEQUENCE:" seq
+  print "LAST-MODIFIED:" zulu
+  print "DTSTART;VALUE=" from_type ":" from
+  print "DTEND;VALUE=" to_type ":" to
+  print_fold("SUMMARY:",     summary,       i, s)
+  print_fold("DESCRIPTION:", desc,          i, s)
+  inside = ""
+}
+{ print }
diff --git a/src/main.sh b/src/main.sh
index b49ace8..6124f1b 100755
--- a/src/main.sh
+++ b/src/main.sh
@@ -93,6 +93,13 @@ EOF
 EOF
   )
   export AWK_GET
+
+  AWK_UPDATE=$(
+    cat <<'EOF'
+@@include src/awk/update.awk
+EOF
+  )
+  export AWK_UPDATE
   ### END OF AWK SCRIPTS
 
   ## Colors
@@ -236,22 +243,31 @@ __list() {
   #  LC_ALL=c xargs -I {} date -d "{}" +"%a %e %b %Y"
 }
 
+__canonical_datetime_hm() {
+  s="$1"
+  t=$(date -d "@$s" +"%R")
+  dfmt="%F"
+  if [ "$t" != "00:00" ]; then
+    dfmt="$dfmt %R"
+  fi
+  date -d "@$s" +"$dfmt"
+}
+
 __canonical_datetime() {
   s="$1"
   shift
   t=$(date -d "@$s" +"%R")
   dfmt="$*%e %b %Y"
   if [ "$t" != "00:00" ]; then
-    dfmt="$dfmt %Y %R %Z"
+    dfmt="$dfmt %R %Z"
   fi
   date -d "@$s" +"$dfmt"
 }
 
 __edit() {
-  start=$(__canonical_datetime "$1")
-  end=$(__canonical_datetime "$2")
+  start=$(__canonical_datetime_hm "$1")
+  end=$(__canonical_datetime_hm "$2")
   fpath="$3"
-  # Use $start $end and $fpath
   summary=$(awk -v field="SUMMARY" "$AWK_GET" "$fpath")
   description=$(awk -v field="DESCRIPTION" "$AWK_GET" "$fpath")
   filetmp=$(mktemp --suffix='.md')
@@ -267,12 +283,9 @@ __edit() {
 
   # Update only if changes are detected
   if [ "$checksum" != "$(cksum "$filetmp")" ]; then
-    # TODO: finish implementation
-    echo "going to update..."
-    read -r tmp
-    #file_new="$filetmp.ics"
-    #awk "$AWK_UPDATE" "$filetmp" "$file" >"$file_new"
-    #mv "$file_new" "$file"
+    filenew="$filetmp.ics"
+    awk "$AWK_UPDATE" "$filetmp" "$fpath" >"$filenew"
+    mv "$filenew" "$fpath"
   fi
   rm "$filetmp"
 }
@@ -332,7 +345,6 @@ if [ "${1:-}" = "--day" ]; then
         --accept-nth='1,2,3,4' \
         --preview="$0 --preview {}" \
         --bind="backspace:first+accept" \
-        --bind="ctrl-n:become($0 --new ${FZF_NTH:-})" \
         --bind="ctrl-s:execute($SYNC_CMD ; printf 'Press <enter> to continue.'; read -r tmp)"
   )
   hour=$(echo "$selection" | cut -d '|' -f 1)
@@ -341,7 +353,6 @@ if [ "${1:-}" = "--day" ]; then
   fpath=$(echo "$selection" | cut -d '|' -f 4 | sed "s/ /|/g")
   if [ -n "$fpath" ]; then
     fpath="$ROOT/$fpath"
-    # TODO: Go on edit file
     __edit "$start" "$end" "$fpath"
   elif [ -n "$hour" ]; then
     # TODO: Go on add entry for hour