Daydreams incorporate recent waking life concerns but do not show delayed ('dream-lag') incorporations.
Consciousness and Cognition February 1, 2018 Elaine Van Rijn, Alexander M Reid, Christopher L Edwards et al.
Daydreams more often incorporate major concerns from the previous two days than from earlier days, supporting a role for daydreams in processing current personal issues. However, personally significant events do not show this day-residue effect in daydreams, and there is no delayed incorporation from 5 to 7 days earlier, unlike what has been found for REM dreams. The study also failed to replicate the previously observed dream-lag effect for REM dreams, possibly due to methodological differences.