Is this safe?

I'm hoping someone with some electrical knowledge might be able to tell me if one of these would be safe to use with a 600w digital ballast.

http://www.homedepot.com/p/Woods-Digital-Outdoor-Block-Heater-Timer-with-Daily-Settings-3-Conductor-Black-50016/203638982

I don't know what the difference is between a block heater timer and any other timer. It says 1875w resistive, so I'm assuming it could handle a 600w MH, but for 18 hours at a time? I really don't know. So here I am, hoping someone could share some knowledge with me.

Thanks in advance for any info.

Block heaters generally use more power than 600watts so u should be more than ok.

As long as your watt rating is above the usage u will be fine..

8 Amp Ballast is the specification it can handle......... you're fine with a 600w ballast

Thanks guys.