What changes.....

[Christian SDA]

What changes did Rabbi Hillel II make, under emperor Constantinius in 350-360 AD, to the yearly, monthly and weekly calendation followed by the Jewish community in their religious observances?

 

[American Gothic]

What changes did Rabbi Hillel II make

there's some info here, not really specific
you might be aware of this already...

Hillel II - Wikipedia

en.wikipedia.org

 

[Jewjitzu]

What changes did Rabbi Hillel II make, under emperor Constantinius in 350-360 AD, to the yearly, monthly and weekly calendation followed by the Jewish community in their religious observances?

https://www.chabad.org/library/article_cdo/aid/526875/jewish/The-Jewish-Calendar-Year.htm

The Sabbath still remains the seventh day.