  Neutrinos generated during solar flares remain elusive. However, after $50$
years of discussion and search, the potential knowledge unleashed by their
discovery keeps the search crucial. Neutrinos associated with solar flares
provide information on otherwise poorly known particle acceleration mechanisms
during solar flare. For neutrino detectors, the separation between atmospheric
neutrinos and solar flare neutrinos is technically encumbered by an energy band
overlap. To improve differentiation from background neutrinos, we developed a
method to determine the temporal search window for neutrino production during
solar flares. Our method is based on data recorded by solar satellites, such as
Geostationary Operational Environmental Satellite (GOES), Reuven Ramaty High
Energy Solar Spectroscopic Imager (RHESSI), and GEOTAIL. In this study, we
selected 23 solar flares above the X5.0 class that occurred between 1996 and
2018. We analyzed the light curves of soft X-rays, hard X-rays, $\gamma$-rays,
line $\gamma$-rays from neutron capture as well as the derivative of soft
X-rays. The average search windows are determined as follows: $4,178$ s for
soft X-ray, $700$ s for derivative of soft X-ray, $944$ s for hard X-ray
($100$-$800$ keV), $1,586$ s for line $\gamma$-ray from neutron captures, and
$776$ s for hard X-ray (above $50$ keV). This method allows neutrino detectors
to improve their sensitivity to solar flare neutrinos.
