To stretch one's circadian rhythm, so it aligns with a normal daylight cycle, but having missed one period. Excessive stimulant use, severe jetlag, or working an unusual shift, can lead to "wrapping it around". Compare to weekend lag, which attempts to compress an already-stretched cycle, rather than stretch it further so that it aligns again.

When you eat dirt for the first time and leave your family to build a shack in the woods