If you clickthrough to the Sleep link: http://www.journalsleep.org/ViewAbstract.aspx?pid=30292 , you can download the fulltext through Sci-hub https://www.dropbox.com/s/sqq41vhyji9pjws/2015-finan.pdf / http://sci-hub.org/downloads/cdac/10.0000@www.journalsleep.o...

The delayed amount was not a fixed amount but calibrated to another subject's total sleep, so you can't say exactly how much each one was delayed by overall:

"RSO During Nights 2–4 of RSO, subjects’ total sleep opportu- nity period was restricted and yoked to the amount of total sleep time achieved by a matched subject in the FA group. This was accomplished by delaying the RSO subject’s bedtime and keeping a fixed wake time. For example, if an FA subject achieved 210 min of total sleep time on Night 2, the yoked RSO subject would be provided a 210-min opportunity for undisturbed sleep (bedtime 03:30, wake time 07:00) on Night 2. Subjects in the RSO condition were monitored polysomno- graphically for an entire 8-h period."