Component of the central CCA1/LHY-TOC1 feedback loop in the circadian clock that promotes clock accuracy and is required for sustained rhythms in the absence of daily light/dark cycles. Homodimer. Follows a light-dependent circadian-regulated expression with a peak at midday, about 6 hours after dawn. Belongs to the EARLY FLOWERING 4 family. Truncated N-terminus. Truncated N-terminus.