increased timer's pecision

plugins/timer/timer.plugin.zsh

+__timer_current_time() {
+  perl -MTime::HiRes=time -e'print time'
+}
+
+__timer_format_duration() {
+  local mins=$(printf '%.0f' $(($1 / 60)))
+  local secs=$(printf '%.1f' $(($1 - 60 * mins)))
+  local duration_str=$(echo "${mins}m${secs}s")
+  echo "\`${duration_str#0m}"
+}
+
 preexec() {
-  __timer_cmd_start_time=$(date '+%s')
+  __timer_cmd_start_time=$(__timer_current_time)
 }
 
 precmd() {
-  if [ -n "$__timer_cmd_start_time" ]; then
-    local cmd_end_time=$(date '+%s')
+  if [ -n "${__timer_cmd_start_time}" ]; then
+    local cmd_end_time=$(__timer_current_time)
     local tdiff=$((cmd_end_time - __timer_cmd_start_time))
     unset __timer_cmd_start_time
-    local tdiffstr="$((tdiff / 60))m$((tdiff % 60))s"
-    local cols=$((COLUMNS - ${#tdiffstr#0m} - 2))
-    echo -e "\033[1A\033[${cols}C \`${tdiffstr#0m}"
+    local tdiffstr=$(__timer_format_duration ${tdiff})
+    local cols=$((COLUMNS - ${#tdiffstr} - 1))
+    echo -e "\033[1A\033[${cols}C ${tdiffstr}"
   fi
 }