"Circadian Rhythm" is a biological phenomenon observed in a large number of organisms ranging from unicellular bacteria to human beings. In this paper, transcriptome data from Cyanothece, a photosynthetic cyanobacteria, has been analyzed for the purpose of discovering genes whose expressions are rhythmically close (co-rhythmic). Subsequently we study if these rhythms can be modeled, up to phase, using a cascade of three phase oscillators. One of the phase oscillator in the network is derived from the model of a "limit cycle oscillator" using KaiC protein (the master clock). We conclude that "Circadian Rhythms in Cyanothece transcriptome data can be dynamically modeled up to phase using a single master clock derived from limit cycle oscillator using KaiC protein cascaded with a pair of interconnected phase oscillators". Biologically substrates of the phase oscillators are presently unknown.