John Moore is taking an extra long weekend, booking off Friday and having pre-recorded programming on the holiday Monday. He announced on Thursday that Jerry Agar would be sitting in for him on the last day of the work week, doing "double duty." 

I'm not quite sure if that means he'll be doing the morning show as well as his own, but if so, that's more than a marathon. Moore's show starts at 5 AM, while Agar's own show doesn't end until noon. A 7-hour shift is a long one no matter how much experience you have, especially in a format where - beyond newscasts and spots - you never get to stop talking. 

I'll be curious to see if they actually make him do this and if so, how he'll sound in the final hour.