int calendar_offset_to_year (int ofs);
int calendar_offset_to_month (int ofs);
int calendar_offset_to_mday (int ofs);
int calendar_offset_to_yday (int ofs);
int calendar_offset_to_wday (int ofs);
int calendar_offset_to_year (int ofs);
int calendar_offset_to_month (int ofs);
int calendar_offset_to_mday (int ofs);
int calendar_offset_to_yday (int ofs);
int calendar_offset_to_wday (int ofs);