Julia doesn’t round based on the day you want but starting on 0000-01-01T00:00:00
https://docs.julialang.org/en/v1/stdlib/Dates/#Rounding-Epoch
What you want is probably something like that
julia> ceil(Time(0,31, 24), Minute(16))
but it is not defined
you can try
julia> ceil(Time(0, 31, 24) - Time(0), Minute(17))