Method: Date#<<

Defined in:

ext/date/date_core.c

#<<(n) ⇒ Object

Returns a date object pointing n months before self. The argument n should be a numeric value.

Date.new(2001,2,3)  <<  1   #=> #<Date: 2001-01-03 ...>
Date.new(2001,2,3)  << -2   #=> #<Date: 2001-04-03 ...>

When the same day does not exist for the corresponding month, the last day of the month is used instead:

Date.new(2001,3,28) << 1   #=> #<Date: 2001-02-28 ...>
Date.new(2001,3,31) << 1   #=> #<Date: 2001-02-28 ...>

This also results in the following, possibly unexpected, behavior:

Date.new(2001,3,31) << 2         #=> #<Date: 2001-01-31 ...>
Date.new(2001,3,31) << 1 << 1    #=> #<Date: 2001-01-28 ...>

Date.new(2001,3,31) << 1 << -1   #=> #<Date: 2001-03-28 ...>

# File 'ext/date/date_core.c', line 6253

static VALUE
d_lite_lshift(VALUE self, VALUE other)
{
    expect_numeric(other);
    return d_lite_rshift(self, f_negate(other));
}