E-mails outside of office hours

Taking inspiration from Mark Reed’s e-mail signature:

I work two evenings a week, so if this email arrives outside office hours, please do not feel you have to reply until normal working hours.

I’ve added this to my own:

I often work unusual hours as my preferred way of balancing multiple roles. If this e-mail arrives outside of office hours, please do not feel obligated to respond until office hours have resumed.

Any thoughts?