The `tmp` script belongs in the `reboot` folder and is used to delete temporary files, Set browsers and other programs to automatically place files in the tmp folder to not manage manual deletion

crontab

# Edit this file to introduce tasks to be run by cron.
# 
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
# 
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').# 
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
# 
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
# 
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
# 
# For more information see the manual pages of crontab(5) and cron(8)
# 
# m h  dom mon dow   command

@reboot  run-parts ~/.config/cron.d/reboot 
@hourly  run-parts ~/.config/cron.d/hourly
@daily   run-parts ~/.config/cron.d/daily
@weekly  run-parts ~/.config/cron.d/monthly
@monthly run-parts ~/.config/cron.d/monthly

tmp

#!/bin/sh

if [ ! -d ~/Downloads/tmp ]; then
  /bin/mkdir -p ~/Downloads/tmp/
fi
/bin/rm -rf ~/Downloads/tmp/*

if [ ! -d ~/Pictures/tmp ]; then
  /bin/mkdir -p ~/Pictures/tmp/
fi
/bin/rm -rf ~/Pictures/tmp/*

if [ ! -d ~/Videos/tmp ]; then
  /bin/mkdir -p ~/Videos/tmp/
fi
/bin/rm -rf ~/Videos/tmp/*