/* vim: set sw=8: -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */ /* * gnm-datetime.c: * * Copyright (C) 2005 * Miguel de Icaza (miguel@gnu.org) * Morten Welinder * Jukka-Pekka Iivonen * Andreas J. Guelzow * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) version 3. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 * USA */ #include #include #include "value.h" #include #include "gnm-datetime.h" #include "gnm-format.h" #include "number-match.h" /* * Figure out whether the format engine in goffice allows negative values * or (as XL) considers them errors. */ gboolean gnm_datetime_allow_negative (void) { static int allow = -1; if (allow == -1) { GOFormat *fmt = go_format_new_from_XL ("yyyy-mm-dd"); GnmValue *v = value_new_int (-42); GODateConventions const *conv = go_date_conv_from_str ("Lotus:1900"); char *text = format_value (fmt, v, -1, conv); allow = (strcmp (text, "1899-11-19") == 0); value_release (v); go_format_unref (fmt); g_free (text); } return (gboolean)allow; } gnm_float datetime_value_to_serial_raw (GnmValue const *v, GODateConventions const *conv) { gnm_float serial; if (VALUE_IS_NUMBER (v)) serial = value_get_as_float (v); else { char const *str = value_peek_string (v); GnmValue *conversion = format_match_number (str, go_format_default_date (), conv); if (conversion) { serial = value_get_as_float (conversion); value_release (conversion); } else serial = G_MAXINT; } if (serial < 0 && !gnm_datetime_allow_negative ()) serial = G_MAXINT; return serial; } /* ------------------------------------------------------------------------- */ int datetime_value_to_serial (GnmValue const *v, GODateConventions const *conv) { gnm_float serial = datetime_value_to_serial_raw (v, conv); if (serial >= G_MAXINT || serial < G_MININT) return G_MAXINT; return go_date_serial_raw_to_serial (serial); } /* ------------------------------------------------------------------------- */ gboolean datetime_value_to_g (GDate *res, GnmValue const *v, GODateConventions const *conv) { int serial = datetime_value_to_serial (v, conv); if (serial == G_MAXINT) { g_date_clear (res, 1); return FALSE; } go_date_serial_to_g (res, serial, conv); return g_date_valid (res); } /* ------------------------------------------------------------------------- */ /* * Returns the number of days in the year for the given date accoring to * the day counting system specified by 'basis' argument. Basis may have * one of the following values: * * 0 for US 30/360 (days in a month/days in a year) * 1 for actual days/actual days * 2 for actual days/360 * 3 for actual days/365 * 4 for European 30/360 * * This function returns 360 for basis 0, 2, and 4, it returns value * 365 for basis 3, and value 365 or 366 for basis 1 accoring to the * year of the given date (366 is returned if the date is in a leap * year). */ int annual_year_basis (GnmValue const *value_date, GOBasisType basis, GODateConventions const *date_conv) { GDate date; switch (basis) { case GO_BASIS_MSRB_30_360: return 360; case GO_BASIS_ACT_ACT: if (!datetime_value_to_g (&date, value_date, date_conv)) return -1; return g_date_is_leap_year (g_date_get_year (&date)) ? 366 : 365; case GO_BASIS_ACT_360: return 360; case GO_BASIS_ACT_365: return 365; case GO_BASIS_30E_360: return 360; default: return -1; } } gnm_float yearfrac (GDate const *from, GDate const *to, GOBasisType basis) { int days; gnm_float peryear; if (!g_date_valid (from) || !g_date_valid (to)) return gnm_nan; days = go_date_days_between_basis (from, to, basis); if (days < 0) { const GDate *tmp; days = -days; tmp = from; from = to; to = tmp; } switch (basis) { case GO_BASIS_ACT_ACT: { int y1 = g_date_get_year (from); int y2 = g_date_get_year (to); GDate d1, d2; int feb29s, years; d1 = *from; gnm_date_add_years (&d1, 1); if (g_date_compare (to, &d1) > 0) { /* More than one year. */ years = y2 + 1 - y1; g_date_clear (&d1, 1); g_date_set_dmy (&d1, 1, 1, y1); g_date_clear (&d2, 1); g_date_set_dmy (&d2, 1, 1, y2 + 1); feb29s = g_date_get_julian (&d2) - g_date_get_julian (&d1) - 365 * (y2 + 1 - y1); } else { /* Less than one year. */ years = 1; if ((g_date_is_leap_year (y1) && g_date_get_month (from) < 3) || (g_date_is_leap_year (y2) && (g_date_get_month (to) * 0x100 + g_date_get_day (to) >= 2 * 0x100 + 29))) feb29s = 1; else feb29s = 0; } peryear = 365 + (gnm_float)feb29s / years; break; } default: peryear = annual_year_basis (NULL, basis, NULL); } return days / peryear; } /* ------------------------------------------------------------------------- */ /* Like g_date_add_days, but... * * 1. Do not spew criticals. * 2. Number of days is signed. */ void gnm_date_add_days (GDate *d, int n) { if (!g_date_valid (d)) return; if (n >= 0) { guint32 lim = 23936166; /* 31-Dec-65535 */ guint32 j = g_date_get_julian (d); if (j > lim || (unsigned)n > lim - j) goto bad; g_date_add_days (d, n); } else { int m = g_date_get_julian (d) - 1; if (m + n <= 0) goto bad; g_date_subtract_days (d, -n); } return; bad: g_date_clear (d, 1); } /* Like g_date_add_months, but... * * 1. Do not spew criticals. * 2. Number of months is signed. */ void gnm_date_add_months (GDate *d, int n) { if (!g_date_valid (d)) return; if (n >= 0) { int m = (65535 - g_date_get_year (d)) * 12 + (12 - g_date_get_month (d)); if (n > m) goto bad; g_date_add_months (d, n); } else { int m = (g_date_get_year (d) - 1) * 12 + (g_date_get_month (d) - 1); if (m + n <= 0) goto bad; g_date_subtract_months (d, -n); } return; bad: g_date_clear (d, 1); } /* Like g_date_add_years, but... * * 1. Do not spew criticals. * 2. Number of years is signed. */ void gnm_date_add_years (GDate *d, int n) { if (!g_date_valid (d)) return; if (n >= 0) { int m = 65535 - g_date_get_year (d); if (n > m) goto bad; g_date_add_years (d, n); } else { int m = g_date_get_year (d) - 1; if (m + n <= 0) goto bad; g_date_subtract_years (d, -n); } return; bad: g_date_clear (d, 1); } #define DAY_SECONDS (3600*24) int datetime_value_to_seconds (GnmValue const *v, GODateConventions const *conv) { int secs; gnm_float d = datetime_value_to_serial_raw (v, conv); if (d >= G_MAXINT || d < G_MININT) return -1; /* Add epsilon before we scale and translate because otherwise it will not be enough. */ d = gnm_add_epsilon (d); /* Get the number down between 0 and 1 before we scale. */ d -= gnm_floor (d); /* Scale and round. */ secs = (int)(gnm_add_epsilon (d) * DAY_SECONDS + 0.5); /* We rounded, so we might have gone too far. */ if (secs >= DAY_SECONDS) secs -= DAY_SECONDS; return secs; }