我有一个时间对象，想找到下个月/上个月.由于每个月的天数不同，加减天数不起作用.
time = Time.parse('21-12-2008 10:51 UTC')
next_month = time + 31 * 24 * 60 * 60
增加月数也会下降，因为你必须注意滚动
time = Time.parse('21-12-2008 10:51 UTC')
next_month = Time.utc(time.year, time.month+1)
time = Time.parse('01-12-2008 10:51 UTC')
previous_month = Time.utc(time.year, time.month-1)
我唯一能找到工作的就是
time = Time.parse('21-12-2008 10:51 UTC')
d = Date.new(time.year, time.month, time.day)
d >>= 1
next_month = Time.utc(d.year, d.month, d.day, time.hour, time.min, time.sec, time.usec)
有没有比这更优雅的方式，我没有看到？