Idle time countdown in conky

.conkyrc

alignment top_left
background no
gap_x 0
gap_y 0
minimum_size 1024 1000
maximum_width 50000

update_interval 2
total_run_times 0
double_buffer yes
#no_buffers yes
text_buffer_size 1248

cpu_avg_samples 2
net_avg_samples 2

use_xft yes
xftfont Quicksand-Regular size=9
xftalpha 0.5
override_utf8_locale yes

own_window yes
own_window_type desktop
own_window_transparent yes

own_window_hints below,undecorated,sticky,skip_taskbar,skip_pager
#below

draw_shades no
draw_outline no
draw_borders no
draw_graph_borders no

default_color 202020
#default_shade_color 7a999c
default_outline_color green

TEXT
${voffset 280}${offset 600}${color #FFFFFF}${execi 600 xprintidle}