Do spaces matter in a crontab
Yes extra space is allowed and you can nicely line up your fields for readability. From man 5 crontab
Blank lines and leading spaces and tabs are ignored.
and
An environment setting is of the form,
name = value
where the spaces around the equal-sign (=) are optional, and any sub‐
sequent non-leading spaces in value will be part of the value assigned
to name.
For the fields itself the man pages says:
The fields may be separated by spaces or tabs.
That should be clear: multiple spaces are allowed.
Yes Extra whitespace is permitted. Consider:
#Mins Hours Days Months Day of the week
10 3 1 1 * /bin/echo "I don't really like cron"
30 16 * 1,2 * /bin/echo "I like cron a little"
* * * 1-12/2 * /bin/echo "I really like cron"
I always add column headers because I'm too lazy to remember the order of all the numbers, but here's what that crontab produces:
This crontab should echo "I really like cron" every minute of every hour of every day every other month(Every Even month). Obviously you would only do that if you really liked cron. The crontab will also echo "I like cron a little" at 16:30 every day in January and February. It will also echo "I don't really like cron" at 3:10 on the January 1st.