Our current overly regimented calendar could usefully be scrapped in its entirety. Few Hindus wish to celebrate Christmas, few Christians observe Yom Kippur, few on the Clapham omnibus make meaningful religious observance of any kind. Political red letter days have little attraction for the bulk of the populace and astronomical/ cultural events such as the equinoxes are unnoticed save by the obsessionally quaint.
Education and the world of work do not benefit from distinct calendars; the sudden press of holiday-makers in school holidays is positively undesirable for a host of reasons.
Why not have uninterrupted industrial and commercial activity running in parallel with uninterrupted all-encompassing but lower-intensity education, every person being entitled to 120 days off per annum at times of their choosing? Workplaces could agree to holiday in rotation or all at once, continuous processes could remain uninterrupted and parents would not be corralled where they can be fleeced by the holiday trade. Religious and cultural requirements would be accommodated with ease.