FFmpeg drawtext pts gmtime not working

Question

I use this command filter on ubuntu 16.4 with php exec to run:

drawtext=fontfile='$local_font_light':text='%{pts\:gmtime\:0\:%M\\\:%S}':fontcolor='#ffffff':fontsize=26:shadowcolor='#000000':shadowx=2:shadowy=2:x=620:y=(685-text_h), fade=t=in:st=2.5:d=1,fade=t=out:st=55:d=1[fadeDuration]

when run no error. but not showing on overlay.

NOTE: this is fix on windows cmd. i use ffmpeg 3.4

i try this answers, but not working.

why?