Derived types and parameters for date and time. More...

Data Types
type	dc_datetime
type	dc_difftime

Variables
Calendar type parameters

integer, parameter, public	cal_cyclic = 1
	Cyclic calendar (30.6 days per month)
integer, parameter, public	cal_noleap = 2
	Calendar without leap years (365 days per year)
integer, parameter, public	cal_julian = 3
	Julian calendar
integer, parameter, public	cal_gregorian = 4
	Gregorian calendar
integer, dimension(0:3), parameter, public	prepared_caltypes = (/CAL_CYCLIC, CAL_NOLEAP, CAL_JULIAN, CAL_GREGORIAN/)
	Array of prepared calendar types
integer, save, public	caltype = CAL_GREGORIAN
	Default calendar type (Gregorian)
Time unit conversion parameters

real(dp), parameter, public	cyclic_mdays = 30.6_DP
	Days per month for cyclic calendar (also used for DC_DIFFTIME)
integer, parameter, public	min_seconds = 60
	Seconds per minute
integer, parameter, public	hour_seconds = 3600
	Seconds per hour
real(dp), parameter, public	day_seconds_earth = 86400.0_DP
	Seconds per day on Earth
real(dp), save, public	day_seconds = DAY_SECONDS_EARTH
	Seconds per day (variable, default is Earth day)
type(dc_scaled_sec), save, public	day_seconds_scl
	Seconds per day (DC_SCALED_SEC type)
logical, save, public	flag_set_day_seconds_scl = .false.
	Flag indicating if day_seconds_scl is set
integer, parameter, public	year_days = 365
	Days per year (non-leap year)
integer, parameter, public	year_months = 12
	Months per year
integer, parameter, public	four_years = YEAR_DAYS * 4 + 1
	Days in 4 years (including leap year)
integer, parameter, public	four_century = YEAR_DAYS * 400 + 97
	Days in 400 years
Unit string parameters

character(*), dimension(1), parameter, public	unit_nondim = (/ '1' /)
	Strings recognized as nondimensional unit
character(*), dimension(8), parameter, public	unit_sec = (/ 'seconds', 'second ', 'secs. ', 'secs ', 'sec. ', 'sec ', 's. ', 's '/)
	Strings recognized as second unit
character(*), dimension(4), parameter, public	unit_min = (/ 'minutes', 'minute ', 'min. ', 'min '/)
	Strings recognized as minute unit
character(*), dimension(8), parameter, public	unit_hour = (/ 'hours', 'hour ', 'hrs. ', 'hrs ', 'hr. ', 'hr ', 'h. ', 'h '/)
	Strings recognized as hour unit
character(*), dimension(4), parameter, public	unit_day = (/ 'days', 'day ', 'd. ', 'd '/)
	Strings recognized as day unit
character(*), dimension(6), parameter, public	unit_month = (/ 'months', 'month ', 'mon. ', 'mon ', 'mo. ', 'mo '/)
	Strings recognized as month unit
character(*), dimension(4), parameter, public	unit_year = (/ 'years', 'year ', 'yr. ', 'yr '/)
	Strings recognized as year unit
Unit symbol parameters

integer, parameter, public	unit_symbol_err = -1
	Symbol for invalid unit
integer, parameter, public	unit_symbol_nondim = 1
	Symbol for nondimensional unit
integer, parameter, public	unit_symbol_sec = 2
	Symbol for second unit
integer, parameter, public	unit_symbol_min = 3
	Symbol for minute unit
integer, parameter, public	unit_symbol_hour = 4
	Symbol for hour unit
integer, parameter, public	unit_symbol_day = 5
	Symbol for day unit
integer, parameter, public	unit_symbol_month = 6
	Symbol for month unit
integer, parameter, public	unit_symbol_year = 7
	Symbol for year unit

Detailed Description

Derived types and parameters for date and time.

Author: Youhei SASAKI, Yasuhiro MORIKAWA, Eizi TOYODA

Copyright: Copyright (C) GFD Dennou Club, 2000-2026. All rights reserved.
License is BSD-2-Clause. see COPYRIGHT in detail

Derived types, variables, parameters for "dc_date" are provided. Calendar information is also managed in this module.

Derived types

Type	Description
DC_DATETIME	Represents date-time as a pair of ordinal day and second
DC_DIFFTIME	Represents time difference like "X months later" or "X days ago"

Unit strings and symbols

Parameter	Description
UNIT_NONDIM	Strings for nondimensional unit
UNIT_SEC	Strings for second unit
UNIT_MIN	Strings for minute unit
UNIT_HOUR	Strings for hour unit
UNIT_DAY	Strings for day unit
UNIT_MONTH	Strings for month unit
UNIT_YEAR	Strings for year unit
UNIT_SYMBOL_*	Integer symbols for units

Calendar parameters

Parameter	Description
CAL_CYCLIC	Cyclic calendar (30.6 days per month)
CAL_NOLEAP	Calendar without leap years (365 days/year)
CAL_JULIAN	Julian calendar
CAL_GREGORIAN	Gregorian calendar

Conversion parameters

Parameter	Description
CYCLIC_MDAYS	Days per month for cyclic calendar (30.6)
DAY_SECONDS_EARTH	Seconds per day on Earth (86400)
MIN_SECONDS	Seconds per minute (60)
HOUR_SECONDS	Seconds per hour (3600)
YEAR_MONTHS	Months per year (12)
YEAR_DAYS	Days per year (non-leap year, 365)
FOUR_YEARS	Days in 4 years
FOUR_CENTURY	Days in 400 years

Variable Documentation

◆ cal_cyclic

integer, parameter, public dc_date_types::cal_cyclic = 1

Cyclic calendar (30.6 days per month)

A calendar where each month has 30.6 days (CYCLIC_MDAYS). (e.g., month 0: 1-30 (30.6), month 1: 1-31 (61.2), month 2: 1-30 (91.8), month 3: 1-31 (122.4), ...) Intended for use in experiments with virtual time.

Definition at line 152 of file dc_date_types.f90.

152 integer, parameter:: CAL_CYCLIC = 1

◆ cal_gregorian

integer, parameter, public dc_date_types::cal_gregorian = 4

Gregorian calendar

Definition at line 164 of file dc_date_types.f90.

164 integer, parameter:: CAL_GREGORIAN = 4

◆ cal_julian

integer, parameter, public dc_date_types::cal_julian = 3

Julian calendar

Definition at line 160 of file dc_date_types.f90.

160 integer, parameter:: CAL_JULIAN = 3

◆ cal_noleap

integer, parameter, public dc_date_types::cal_noleap = 2

Calendar without leap years (365 days per year)

Definition at line 156 of file dc_date_types.f90.

156 integer, parameter:: CAL_NOLEAP = 2

◆ caltype

integer, save, public dc_date_types::caltype = CAL_GREGORIAN

Default calendar type (Gregorian)

Definition at line 173 of file dc_date_types.f90.

173 integer, save:: caltype = cal_gregorian

◆ cyclic_mdays

real(dp), parameter, public dc_date_types::cyclic_mdays = 30.6_DP

Days per month for cyclic calendar (also used for DC_DIFFTIME)

Definition at line 188 of file dc_date_types.f90.

188 real(DP), parameter:: CYCLIC_MDAYS = 30.6_dp

◆ day_seconds

real(dp), save, public dc_date_types::day_seconds = DAY_SECONDS_EARTH

Seconds per day (variable, default is Earth day)

Definition at line 204 of file dc_date_types.f90.

204 real(DP), save :: day_seconds = day_seconds_earth

◆ day_seconds_earth

real(dp), parameter, public dc_date_types::day_seconds_earth = 86400.0_DP

Seconds per day on Earth

Definition at line 200 of file dc_date_types.f90.

200 real(DP), parameter:: DAY_SECONDS_EARTH = 86400.0_dp

◆ day_seconds_scl

type(dc_scaled_sec), save, public dc_date_types::day_seconds_scl

Seconds per day (DC_SCALED_SEC type)

Definition at line 208 of file dc_date_types.f90.

208 type(DC_SCALED_SEC), save :: day_seconds_scl

◆ flag_set_day_seconds_scl

logical, save, public dc_date_types::flag_set_day_seconds_scl = .false.

Flag indicating if day_seconds_scl is set

Definition at line 212 of file dc_date_types.f90.

212 logical, save :: flag_set_day_seconds_scl = .false.

◆ four_century

integer, parameter, public dc_date_types::four_century = YEAR_DAYS * 400 + 97

Days in 400 years

Definition at line 228 of file dc_date_types.f90.

228 integer, parameter:: FOUR_CENTURY = year_days * 400 + 97

◆ four_years

integer, parameter, public dc_date_types::four_years = YEAR_DAYS * 4 + 1

Days in 4 years (including leap year)

Definition at line 224 of file dc_date_types.f90.

224 integer, parameter:: FOUR_YEARS = year_days * 4 + 1

◆ hour_seconds

integer, parameter, public dc_date_types::hour_seconds = 3600

Seconds per hour

Definition at line 196 of file dc_date_types.f90.

196 integer, parameter:: HOUR_SECONDS = 3600

◆ min_seconds

integer, parameter, public dc_date_types::min_seconds = 60

Seconds per minute

Definition at line 192 of file dc_date_types.f90.

192 integer, parameter:: MIN_SECONDS = 60

◆ prepared_caltypes

integer, dimension(0:3), parameter, public dc_date_types::prepared_caltypes = (/CAL_CYCLIC, CAL_NOLEAP, CAL_JULIAN, CAL_GREGORIAN/)

Array of prepared calendar types

Definition at line 168 of file dc_date_types.f90.

168 integer, parameter:: PREPARED_CALTYPES(0:3) = &

169 & (/CAL_CYCLIC, CAL_NOLEAP, CAL_JULIAN, CAL_GREGORIAN/)

◆ unit_day

character(*), dimension(4), parameter, public dc_date_types::unit_day = (/ 'days', 'day ', 'd. ', 'd '/)

Strings recognized as day unit

Definition at line 265 of file dc_date_types.f90.

265 character(*), parameter, dimension(4) :: UNIT_DAY = (/ &

266 & 'days', 'day ', 'd. ', 'd '/)

◆ unit_hour

character(*), dimension(8), parameter, public dc_date_types::unit_hour = (/ 'hours', 'hour ', 'hrs. ', 'hrs ', 'hr. ', 'hr ', 'h. ', 'h '/)

Strings recognized as hour unit

Definition at line 259 of file dc_date_types.f90.

  character(*), parameter, dimension(8) :: UNIT_HOUR = (/ &
    & 'hours', 'hour ', 'hrs. ', 'hrs  ', &
    & 'hr.  ', 'hr   ', 'h.   ', 'h    '/)

◆ unit_min

character(*), dimension(4), parameter, public dc_date_types::unit_min = (/ 'minutes', 'minute ', 'min. ', 'min '/)

Strings recognized as minute unit

Definition at line 254 of file dc_date_types.f90.

254 character(*), parameter, dimension(4) :: UNIT_MIN = (/ &

255 & 'minutes', 'minute ', 'min. ', 'min '/)

◆ unit_month

character(*), dimension(6), parameter, public dc_date_types::unit_month = (/ 'months', 'month ', 'mon. ', 'mon ', 'mo. ', 'mo '/)

Strings recognized as month unit

Definition at line 270 of file dc_date_types.f90.

  character(*), parameter, dimension(6) :: UNIT_MONTH = (/ &
    & 'months', 'month ', 'mon.  ', &
    & 'mon   ', 'mo.   ', 'mo    '/)

◆ unit_nondim

character(*), dimension(1), parameter, public dc_date_types::unit_nondim = (/ '1' /)

Strings recognized as nondimensional unit

Definition at line 243 of file dc_date_types.f90.

243 character(*), parameter, dimension(1) :: UNIT_NONDIM = (/ &

244 & '1' /)

◆ unit_sec

character(*), dimension(8), parameter, public dc_date_types::unit_sec = (/ 'seconds', 'second ', 'secs. ', 'secs ', 'sec. ', 'sec ', 's. ', 's '/)

Strings recognized as second unit

Definition at line 248 of file dc_date_types.f90.

  character(*), parameter, dimension(8) :: UNIT_SEC = (/ &
    & 'seconds', 'second ', 'secs.  ', 'secs   ', &
    & 'sec.   ', 'sec    ', 's.     ', 's      '/)

◆ unit_symbol_day

integer, parameter, public dc_date_types::unit_symbol_day = 5

Symbol for day unit

Definition at line 312 of file dc_date_types.f90.

312 integer, parameter:: UNIT_SYMBOL_DAY = 5

◆ unit_symbol_err

integer, parameter, public dc_date_types::unit_symbol_err = -1

Symbol for invalid unit

Definition at line 292 of file dc_date_types.f90.

292 integer, parameter:: UNIT_SYMBOL_ERR = -1

◆ unit_symbol_hour

integer, parameter, public dc_date_types::unit_symbol_hour = 4

Symbol for hour unit

Definition at line 308 of file dc_date_types.f90.

308 integer, parameter:: UNIT_SYMBOL_HOUR = 4

◆ unit_symbol_min

integer, parameter, public dc_date_types::unit_symbol_min = 3

Symbol for minute unit

Definition at line 304 of file dc_date_types.f90.

304 integer, parameter:: UNIT_SYMBOL_MIN = 3

◆ unit_symbol_month

integer, parameter, public dc_date_types::unit_symbol_month = 6

Symbol for month unit

Definition at line 316 of file dc_date_types.f90.

316 integer, parameter:: UNIT_SYMBOL_MONTH = 6

◆ unit_symbol_nondim

integer, parameter, public dc_date_types::unit_symbol_nondim = 1

Symbol for nondimensional unit

Definition at line 296 of file dc_date_types.f90.

296 integer, parameter:: UNIT_SYMBOL_NONDIM = 1

◆ unit_symbol_sec

integer, parameter, public dc_date_types::unit_symbol_sec = 2

Symbol for second unit

Definition at line 300 of file dc_date_types.f90.

300 integer, parameter:: UNIT_SYMBOL_SEC = 2

◆ unit_symbol_year

integer, parameter, public dc_date_types::unit_symbol_year = 7

Symbol for year unit

Definition at line 320 of file dc_date_types.f90.

320 integer, parameter:: UNIT_SYMBOL_YEAR = 7

◆ unit_year

character(*), dimension(4), parameter, public dc_date_types::unit_year = (/ 'years', 'year ', 'yr. ', 'yr '/)

Strings recognized as year unit

Definition at line 276 of file dc_date_types.f90.

276 character(*), parameter, dimension(4) :: UNIT_YEAR = (/ &

277 & 'years', 'year ', 'yr. ', 'yr '/)

◆ year_days

integer, parameter, public dc_date_types::year_days = 365

Days per year (non-leap year)

Definition at line 216 of file dc_date_types.f90.

216 integer, parameter:: YEAR_DAYS = 365

◆ year_months

integer, parameter, public dc_date_types::year_months = 12

Months per year

Definition at line 220 of file dc_date_types.f90.

220 integer, parameter:: YEAR_MONTHS = 12

Data Types

Variables