It surprises me that nobody has the correct answer to this. Today i faced exactly the same problem and google didn’t help.
After 2 hours i found that when placing a file in /etc/cron.d the schedule line has to contain an extra option…..
I allways use this for my crontab -e
# Minute Hour Day of Month Month Day of Week Command
# (0-59) (0-23) (1-31) (1-12 or Jan-Dec) (0-6 or Sun-Sat) /my/fancy/script.sh
So it contains 6 items.
When placing this in a file inside /etc/cron.d the cron needs an extra option, being the user to run your fancy/script.
# Minute Hour Day of Month Month Day of Week Who Command
# (0-59) (0-23) (1-31) (1-12 or Jan-Dec) (0-6 or Sun-Sat) root /my/fancy/script.sh
This is documented in man crontab(5). For example https://linux.die.net/man/5/crontab . It says:
Jobs in /etc/cron.d/
The jobs in cron.d are system jobs, which are used usually for more than one user. That’s the reason why is name of the user needed. MAILTO on the first line is optional.