Who had invented or made true solar calendar in Mughal period?
Akbar's royal astronomer Fathullah Shirazi developed the Bengali calendar, by synthesizing the Lunar Islamic and Solar Hindu calendars. The calendar started with the Islamic calendar value, but the Sanskrit month names were used from the earlier version. The distinctive characteristic of the Bengali year was that rather than being a lunar calendar, it was based on a union of the solar and lunar year. This was essentially a great promotion as the solar and lunar years were formulated in very diverse systems.