liquidsoap schedule issue

Hello,
I use a  liquidsoap script to stream when nothing is scheduled on Airtime. It works fine but sometime I face liquidsoap schedule issue (but not always).
There is a delay on time (arround 10 or 20 minutes).To fix this issue I have scheduled on crontab to restart the liquidsoap deamon every day, but without success.

Here is the main part of my liquidsoap script

//////////////////////
# define playlist for show
mix_list                  = playlist(mode='randomize', reload=43200, "/srv/airtime/autodj/mix/")
show_rb1                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb1.m3u")
show_rb2                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb2.m3u")
show_rb3                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb3.m3u")
show_rb5                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb5.m3u")
show_rb6                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb6.m3u")
show_rb7                = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_rb7.m3u")
show_annonce        = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_annonce.m3u")
show_matinale           = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_matinale.m3u")
show_quotidienne        = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_quotidienne.m3u")
show_temoignage         = playlist(mode="normal", reload=3600, "/srv/airtime/autodj/playlist/playlist_temoignage.m3u")

# Schedule
default = fallback(track_sensitive=false, [queue,
        switch([
                ({6h00-6h45}, show_annonce),
                ({7h30-7h45}, show_rb6),
                ({8h30-8h45}, show_rb6),
                ({9h00-10h00}, show_matinale),
                ({16h00-16h15}, show_rb2),
                ({19h00-19h15}, show_rb6),
                ({20h00-21h00}, show_quotidienne),
                ({23h00-23h45}, show_annonce),
                ({(1w or 5w) and 15h00-15h15}, show_temoignage),
                ({(2w) and 15h00-15h15}, show_rb5),
                ({(3w or 7w) and 15h00-15h15}, show_rb3),
                ({(4w) and 15h00-15h15}, show_rb7),
                ({(6w) and 15h00-15h15}, show_rb1)]),
        mix_list])
/////////////////////////////

Thanks in advance for your help.