Many indirect astronomical and cosmological observations, such as measurements of rotational curves of spiral galaxies and gravitational lensing, introduce substantial evidence for the existence of dark matter. Expected experimental signatures of dark matter, according to the Standard Halo Model, consist of annual and diurnal modulation. A previously developed optomechanical detector with silicon nitride, platinum-coated membrane was employed in a four-month-long data-taking campaign focused on obtaining hypothesized time-dependent dark matter signals. The membrane displacement is detected by the modified Michelson interferometer and optical homodyne technique. The main observable in this experimental setup is frecquency of a membrane’s thermally induced resonant peak. Due to a large amount of stored data, the implementation of parallel computing in dedicated Python code was crucial to obtain relevant dataset used in the proceeding steps of the analysis pipeline. After the automated analysis was done on supercomputer BURA, local optimized analysis using two independent methods followed. Here either the Lomb-Scargle periodogram is calculated or, the data points are folded using a 24 hour period in terms of local synodic and sidereal time. A presence of daily modulation in frequency measurements as a function of local sidereal time is reported at a range of room temperatures. Characterization of modulated signal suggests a period of oscillation (0,52 ± 0,02) rad/h consistent with daily modulation interpretation of a dark matter signal measured by Earth-based detector. Further measurements and discussions are necessary concerning possible background contributions, mass upper-limit as well as confirmation of dark matter flux interpretation of the interaction with the detector membrane.