End of Life Ruby 3.2 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

Date#julian?

d.julian? → true or false

static VALUE
d_lite_julian_p(VALUE self)
{
    get_d1(self);
    return f_boolcast(m_julian_p(dat));
}

Returns true if the date is before the date of calendar reform, false otherwise:

Example

(Date.new(1582, 10, 15) - 1).julian? # => true
Date.new(1582, 10, 15).julian?       # => false

See also #julian #ld #jisx0301 #leap? also in 4.1 · 4.0 · 3.4 · 3.3 · 3.1 · 3.0