Increase precision of time handling

src/core/MOM.F90

@@ -39,7 +39,7 @@ module MOM
 use MOM_restart,              only : register_restart_field, query_initialized, save_restart
 use MOM_restart,              only : restart_init, is_new_run, MOM_restart_CS
 use MOM_spatial_means,        only : global_mass_integral
-use MOM_time_manager,         only : time_type, set_time, time_type_to_real, operator(+)
+use MOM_time_manager,         only : time_type, real_to_time, time_type_to_real, operator(+)
 use MOM_time_manager,         only : operator(-), operator(>), operator(*), operator(/)
 use MOM_time_manager,         only : operator(>=), increment_date
 use MOM_unit_tests,           only : unit_tests
@@ -556,7 +556,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
     do j=js,je ; do i=is,ie ; CS%ssh_rint(i,j) = 0.0 ; enddo ; enddo
 
     if (associated(CS%VarMix)) then
-      call enable_averaging(cycle_time, Time_start+set_time(int(cycle_time)), &
+      call enable_averaging(cycle_time, Time_start + real_to_time(cycle_time), &
                             CS%diag)
       call calc_resoln_function(h, CS%tv, G, GV, CS%VarMix)
       call disable_averaging(CS%diag)
@@ -582,7 +582,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
 
     if (CS%UseWaves) then
       ! Update wave information, which is presently kept static over each call to step_mom
-      call enable_averaging(time_interval, Time_start + set_time(int(floor(time_interval+0.5))), CS%diag)
+      call enable_averaging(time_interval, Time_start + real_to_time(time_interval), CS%diag)
       call Update_Stokes_Drift(G, GV, Waves, h, forces%ustar)
       call disable_averaging(CS%diag)
     endif
@@ -604,9 +604,9 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
   do n=1,n_max
     rel_time = rel_time + dt ! The relative time at the end of the step.
     ! Set the universally visible time to the middle of the time step.
-    CS%Time = Time_start + set_time(int(floor(0.5 + rel_time - 0.5*dt)))
+    CS%Time = Time_start + real_to_time(rel_time - 0.5*dt)
     ! Set the local time to the end of the time step.
-    Time_local = Time_start + set_time(int(floor(rel_time+0.5)))
+    Time_local = Time_start + real_to_time(rel_time)
 
     if (showCallTree) call callTree_enter("DT cycles (step_MOM) n=",n)
 
@@ -633,10 +633,10 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
       if (dtdia > dt) then
         ! If necessary, temporarily reset CS%Time to the center of the period covered
         ! by the call to step_MOM_thermo, noting that they begin at the same time.
-        CS%Time = CS%Time + set_time(int(floor(0.5*(dtdia-dt) + 0.5)))
+        CS%Time = CS%Time + real_to_time(0.5*(dtdia-dt))
         ! The end-time of the diagnostic interval needs to be set ahead if there
         ! are multiple dynamic time steps worth of thermodynamics applied here.
-        end_time_thermo = Time_local + set_time(int(floor(dtdia-dt+0.5)))
+        end_time_thermo = Time_local + real_to_time(dtdia-dt)
       endif
 
       ! Apply diabatic forcing, do mixing, and regrid.
@@ -649,7 +649,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
       if (showCallTree) call callTree_waypoint("finished diabatic_first (step_MOM)")
 
       if (dtdia > dt) & ! Reset CS%Time to its previous value.
-        CS%Time = Time_start + set_time(int(floor(0.5 + rel_time - 0.5*dt)))
+        CS%Time = Time_start + real_to_time(rel_time - 0.5*dt)
     endif ! end of block "(CS%diabatic_first .and. (CS%t_dyn_rel_adv==0.0))"
 
     if (do_dyn) then
@@ -731,7 +731,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
 
       ! If necessary, temporarily reset CS%Time to the center of the period covered
       ! by the call to step_MOM_thermo, noting that they end at the same time.
-      if (dtdia > dt) CS%Time = CS%Time - set_time(int(floor(0.5*(dtdia-dt) + 0.5)))
+      if (dtdia > dt) CS%Time = CS%Time - real_to_time(0.5*(dtdia-dt))
 
       ! Apply diabatic forcing, do mixing, and regrid.
       call step_MOM_thermo(CS, G, GV, u, v, h, CS%tv, fluxes, dtdia, &
@@ -740,7 +740,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
       CS%t_dyn_rel_thermo = 0.0
 
       if (dtdia > dt) & ! Reset CS%Time to its previous value.
-        CS%Time = Time_start + set_time(int(floor(0.5 + rel_time - 0.5*dt)))
+        CS%Time = Time_start + real_to_time(rel_time - 0.5*dt)
     endif
 
     if (do_dyn) then
@@ -774,7 +774,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
       CS%t_dyn_rel_diag = 0.0
 
       call cpu_clock_begin(id_clock_Z_diag)
-      if (Time_local + set_time(int(0.5*dt_therm)) > CS%Z_diag_time) then
+      if (Time_local + real_to_time(0.5*dt_therm) > CS%Z_diag_time) then
         call enable_averaging(real(time_type_to_real(CS%Z_diag_interval)), &
                               CS%Z_diag_time, CS%diag)
       !### This is the one place where fluxes might used if do_thermo=.false. Is this correct?
@@ -852,7 +852,7 @@ subroutine step_MOM(forces, fluxes, sfc_state, Time_start, time_interval, CS, &
   if (MOM_state_is_synchronized(CS)) &
     call write_energy(CS%u, CS%v, CS%h, CS%tv, Time_local, CS%nstep_tot, &
                       G, GV, CS%sum_output_CSp, CS%tracer_flow_CSp, &
-                      dt_forcing=set_time(int(floor(time_interval+0.5))) )
+                      dt_forcing=real_to_time(time_interval) )
 
   call cpu_clock_end(id_clock_other)
 
@@ -912,7 +912,7 @@ subroutine step_MOM_dynamics(forces, p_surf_begin, p_surf_end, dt, dt_thermo, &
 
   if ((CS%t_dyn_rel_adv == 0.0) .and. CS%thickness_diffuse .and. CS%thickness_diffuse_first) then
 
-    call enable_averaging(dt_thermo, Time_local+set_time(int(floor(dt_thermo-dt+0.5))), CS%diag)
+    call enable_averaging(dt_thermo, Time_local+real_to_time(dt_thermo-dt), CS%diag)
     call cpu_clock_begin(id_clock_thick_diff)
     if (associated(CS%VarMix)) &
       call calc_slope_functions(h, CS%tv, dt, G, GV, CS%VarMix)
@@ -931,7 +931,7 @@ subroutine step_MOM_dynamics(forces, p_surf_begin, p_surf_end, dt, dt_thermo, &
   ! The bottom boundary layer properties need to be recalculated.
   if (bbl_time_int > 0.0) then
     call enable_averaging(bbl_time_int, &
-              Time_local + set_time(int(bbl_time_int-dt+0.5)), CS%diag)
+              Time_local + real_to_time(bbl_time_int-dt), CS%diag)
     ! Calculate the BBL properties and store them inside visc (u,h).
     call cpu_clock_begin(id_clock_BBL_visc)
     call set_viscous_BBL(CS%u, CS%v, CS%h, CS%tv, CS%visc, G, GV, &
@@ -2286,7 +2286,7 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
               CS%OBC, CS%update_OBC_CSp, CS%ALE_CSp, CS%set_visc_CSp,        &
               CS%visc, dirs, CS%ntrunc, calc_dtbt=calc_dtbt)
     if (CS%dtbt_reset_period > 0.0) then
-      CS%dtbt_reset_interval = set_time(int(floor(CS%dtbt_reset_period)))
+      CS%dtbt_reset_interval = real_to_time(CS%dtbt_reset_period)
       ! Set dtbt_reset_time to be the next even multiple of dtbt_reset_interval.
       CS%dtbt_reset_time = Time_init + CS%dtbt_reset_interval * &
                                  ((Time - Time_init) / CS%dtbt_reset_interval)
@@ -2325,11 +2325,10 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
                             param_file, diag, CS%diagnostics_CSp, CS%tv)
   call diag_copy_diag_to_storage(CS%diag_pre_sync, CS%h, CS%diag)
 
-  CS%Z_diag_interval = set_time(int((CS%dt_therm) * &
-       max(1,floor(0.01 + Z_diag_int/(CS%dt_therm)))))
+  CS%Z_diag_interval = real_to_time(CS%dt_therm * max(1,floor(0.01 + Z_diag_int/CS%dt_therm)))
   call MOM_diag_to_Z_init(Time, G, GV, param_file, diag, CS%diag_to_Z_CSp)
   CS%Z_diag_time = Start_time + CS%Z_diag_interval * (1 + &
-    ((Time + set_time(int(CS%dt_therm))) - Start_time) / CS%Z_diag_interval)
+    ((Time + real_to_time(CS%dt_therm)) - Start_time) / CS%Z_diag_interval)
 
   if (associated(CS%sponge_CSp)) &
     call init_sponge_diags(Time, G, diag, CS%sponge_CSp)

src/core/MOM_barotropic.F90

@@ -22,7 +22,7 @@ module MOM_barotropic
 use MOM_open_boundary, only : OBC_DIRECTION_N, OBC_DIRECTION_S, OBC_segment_type
 use MOM_restart, only : register_restart_field, query_initialized, MOM_restart_CS
 use MOM_tidal_forcing, only : tidal_forcing_sensitivity, tidal_forcing_CS
-use MOM_time_manager, only : time_type, set_time, operator(+), operator(-)
+use MOM_time_manager, only : time_type, real_to_time, operator(+), operator(-)
 use MOM_variables, only : BT_cont_type, alloc_bt_cont_type
 use MOM_verticalGrid, only : verticalGrid_type
 
@@ -723,7 +723,7 @@ subroutine btstep(U_in, V_in, eta_in, dt, bc_accel_u, bc_accel_v, &
       (CS%id_uhbt_hifreq > 0) .or. (CS%id_vhbt_hifreq > 0)) then
     do_hifreq_output = query_averaging_enabled(CS%diag, time_int_in, time_end_in)
     if (do_hifreq_output) &
-      time_bt_start = time_end_in - set_time(int(floor(dt+0.5)))
+      time_bt_start = time_end_in - real_to_time(dt)
   endif
 
 !--- begin setup for group halo update
@@ -2008,7 +2008,7 @@ subroutine btstep(U_in, V_in, eta_in, dt, bc_accel_u, bc_accel_v, &
     enddo ; enddo
 
     if (do_hifreq_output) then
-      time_step_end = time_bt_start + set_time(int(floor(n*dtbt+0.5)))
+      time_step_end = time_bt_start + real_to_time(n*dtbt)
       call enable_averaging(dtbt, time_step_end, CS%diag)
       if (CS%id_ubt_hifreq > 0) call post_data(CS%id_ubt_hifreq, ubt(IsdB:IedB,jsd:jed), CS%diag)
       if (CS%id_vbt_hifreq > 0) call post_data(CS%id_vbt_hifreq, vbt(isd:ied,JsdB:JedB), CS%diag)

src/core/MOM_dynamics_split_RK2.F90

@@ -30,7 +30,7 @@ module MOM_dynamics_split_RK2
 use MOM_io,                only : MOM_io_init, vardesc, var_desc
 use MOM_restart,           only : register_restart_field, query_initialized, save_restart
 use MOM_restart,           only : restart_init, is_new_run, MOM_restart_CS
-use MOM_time_manager,      only : time_type, set_time, time_type_to_real, operator(+)
+use MOM_time_manager,      only : time_type, time_type_to_real, operator(+)
 use MOM_time_manager,      only : operator(-), operator(>), operator(*), operator(/)
 
 use MOM_ALE,                   only : ALE_CS

src/core/MOM_dynamics_unsplit.F90

@@ -72,7 +72,7 @@ module MOM_dynamics_unsplit
 use MOM_io, only : MOM_io_init
 use MOM_restart, only : register_restart_field, query_initialized, save_restart
 use MOM_restart, only : restart_init, MOM_restart_CS
-use MOM_time_manager, only : time_type, set_time, time_type_to_real, operator(+)
+use MOM_time_manager, only : time_type, real_to_time, operator(+)
 use MOM_time_manager, only : operator(-), operator(>), operator(*), operator(/)
 
 use MOM_ALE, only : ALE_CS
@@ -267,7 +267,7 @@ subroutine step_MOM_dyn_unsplit(u, v, h, tv, visc, Time_local, dt, forces, &
   call pass_var(hp, G%Domain, clock=id_clock_pass)
   call pass_vector(uh, vh, G%Domain, clock=id_clock_pass)
 
-  call enable_averaging(0.5*dt,Time_local-set_time(int(0.5*dt)), CS%diag)
+  call enable_averaging(0.5*dt,Time_local-real_to_time(0.5*dt), CS%diag)
 !   Here the first half of the thickness fluxes are offered for averaging.
   if (CS%id_uh > 0) call post_data(CS%id_uh, uh, CS%diag)
   if (CS%id_vh > 0) call post_data(CS%id_vh, vh, CS%diag)

src/core/MOM_dynamics_unsplit_RK2.F90

@@ -70,7 +70,7 @@ module MOM_dynamics_unsplit_RK2
 use MOM_io, only : MOM_io_init
 use MOM_restart, only : register_restart_field, query_initialized, save_restart
 use MOM_restart, only : restart_init, MOM_restart_CS
-use MOM_time_manager, only : time_type, set_time, time_type_to_real, operator(+)
+use MOM_time_manager, only : time_type, time_type_to_real, operator(+)
 use MOM_time_manager, only : operator(-), operator(>), operator(*), operator(/)
 
 use MOM_ALE, only : ALE_CS

src/framework/MOM_file_parser.F90

@@ -6,8 +6,8 @@ module MOM_file_parser
 use MOM_coms, only : root_PE, broadcast
 use MOM_error_handler, only : MOM_error, FATAL, WARNING, MOM_mesg
 use MOM_error_handler, only : is_root_pe, stdlog, stdout
-use MOM_time_manager, only : set_time, get_time, time_type, get_ticks_per_second
-use MOM_time_manager, only : set_date, get_date
+use MOM_time_manager, only : get_time, time_type, get_ticks_per_second
+use MOM_time_manager, only : set_date, get_date, real_to_time, operator(-), set_time
 use MOM_document, only : doc_param, doc_module, doc_init, doc_end, doc_type
 use MOM_document, only : doc_openBlock, doc_closeBlock
 use MOM_string_functions, only : left_int, left_ints, slasher
@@ -821,7 +821,7 @@ subroutine read_param_time(CS, varname, value, timeunit, fail_if_missing, date_f
   character(len=240) :: err_msg
   logical            :: found, defined
   real               :: real_time, time_unit
-  integer            :: days, secs, vals(7)
+  integer            :: vals(7)
 
   if (present(date_format)) date_format = .false.
 
@@ -854,10 +854,8 @@ subroutine read_param_time(CS, varname, value, timeunit, fail_if_missing, date_f
     else
       time_unit = 1.0 ; if (present(timeunit)) time_unit = timeunit
       read( value_string(1), *) real_time
-      days = int(real_time*(time_unit/86400.0))
-      secs = int(floor((real_time*(time_unit/86400.0)-days)*86400.0 + 0.5))
-      value = set_time(secs, days)
-   endif
+      value = real_to_time(real_time*time_unit)
+    endif
   else
     if (present(fail_if_missing)) then ; if (fail_if_missing) then
       if (.not.found) then

src/framework/MOM_horizontal_regridding.F90

@@ -19,7 +19,7 @@ module MOM_horizontal_regridding
 use MOM_io, only : open_file, read_data, read_axis_data, SINGLE_FILE, MULTIPLE
 use MOM_io, only : slasher, vardesc, write_field
 use MOM_string_functions, only : uppercase
-use MOM_time_manager, only : time_type, set_time, get_external_field_size
+use MOM_time_manager, only : time_type, get_external_field_size
 use MOM_time_manager, only : init_external_field, time_interp_external
 use MOM_time_manager, only : get_external_field_axes, get_external_field_missing
 use MOM_variables, only : thermo_var_ptrs

src/framework/MOM_restart.F90

@@ -14,8 +14,8 @@ module MOM_restart
 use MOM_io, only : vardesc, var_desc, query_vardesc, modify_vardesc
 use MOM_io, only : MULTIPLE, NETCDF_FILE, READONLY_FILE, SINGLE_FILE
 use MOM_io, only : CENTER, CORNER, NORTH_FACE, EAST_FACE
-use MOM_time_manager, only : time_type, get_time, get_date, set_date, set_time
-use MOM_time_manager, only : days_in_month
+use MOM_time_manager, only : time_type, time_type_to_real, real_to_time
+use MOM_time_manager, only : days_in_month, get_date, set_date
 use MOM_verticalGrid, only : verticalGrid_type
 use mpp_mod,         only:  mpp_chksum
 use mpp_io_mod,      only:  mpp_attribute_exist, mpp_get_atts
@@ -801,15 +801,14 @@ subroutine save_restart(directory, time, G, CS, time_stamped, filename, GV)
 
   ! With parallel read & write, it is possible to disable the following...
 
-! jgj: this was set to 4294967292, changed to 4294967295 (see mpp_parameter.F90)
-  if (CS%large_file_support) max_file_size = 4294967295_8
+  ! The maximum file size is 4294967292, according to the NetCDF documentation.
+  if (CS%large_file_support) max_file_size = 4294967292_8
 
   num_files = 0
   next_var = 0
   nz = 1 ; if (present(GV)) nz = GV%ke
 
-  call get_time(time,seconds,days)
-  restart_time = real(days) + real(seconds)/86400.0
+  restart_time = time_type_to_real(time) / 86400.0
 
   restartname = trim(CS%restartfile)
   if (present(filename)) restartname = trim(filename)
@@ -982,7 +981,7 @@ subroutine restore_state(filename, directory, day, G, CS)
   character(len=80) :: varname    ! A variable's name.
   integer :: num_file        ! The number of files (restart files and others
                              ! explicitly in filename) that are open.
-  integer :: i, n, m, start_of_day, num_days, missing_fields
+  integer :: i, n, m, missing_fields
   integer :: isL, ieL, jsL, jeL, is0, js0
   integer :: sizes(7)
   integer :: ndim, nvar, natt, ntime, pos
@@ -1028,9 +1027,7 @@ subroutine restore_state(filename, directory, day, G, CS)
     t1 = time_vals(1)
     deallocate(time_vals)
 
-    start_of_day = INT((t1 - INT(t1)) *86400) ! Number of seconds.
-    num_days = INT(t1)
-    day = set_time(start_of_day, num_days)
+    day = real_to_time(t1*86400.0)
     exit
   enddo
 

src/framework/MOM_time_manager.F90

@@ -20,8 +20,9 @@ module MOM_time_manager
 
 implicit none ; private
 
-public :: time_type, get_time, set_time, time_type_to_real, real_to_time_type
-public :: set_ticks_per_second , get_ticks_per_second
+public :: time_type, get_time, set_time
+public :: time_type_to_real, real_to_time_type, real_to_time
+public :: set_ticks_per_second, get_ticks_per_second
 public :: operator(+), operator(-), operator(*), operator(/)
 public :: operator(>), operator(<), operator(>=), operator(<=)
 public :: operator(==), operator(/=), operator(//)
@@ -35,4 +36,29 @@ module MOM_time_manager
 public :: get_external_field_axes
 public :: get_external_field_missing
 
+contains
+
+!> This is an alternate implementation of the FMS function real_to_time_type that is accurate over
+!! a larger range of input values.  With 32 bit signed integers, this version should work over the
+!! entire valid range (2^31 days or ~5.8835 million years) of time_types, whereas the standard
+!! version in the FMS time_manager stops working for conversions of times greater than 2^31 seconds,
+!! or ~68.1 years.
+function real_to_time(x, err_msg)
+  type(time_type)  :: real_to_time !< The output time as a time_type
+  real, intent(in) :: x            !< The input time in real seconds.
+  character(len=*), intent(out), optional :: err_msg !< An optional returned error message.
+
+  ! Local variables
+  integer          :: seconds, days, ticks
+  real             :: real_subsecond_remainder
+
+  days = floor(x/86400.)
+  seconds = floor(x - 86400.*days)
+  real_subsecond_remainder = x - (days*86400. + seconds)
+  ticks = nint(real_subsecond_remainder * get_ticks_per_second())
+
+  real_to_time = set_time(seconds=seconds, days=days, ticks=ticks, err_msg=err_msg)
+end function real_to_time
+
+
 end module MOM_time_manager

src/ice_shelf/MOM_ice_shelf.F90

@@ -25,7 +25,7 @@ module MOM_ice_shelf
 use MOM_io, only : write_field, close_file, SINGLE_FILE, MULTIPLE
 use MOM_restart, only : register_restart_field, query_initialized, save_restart
 use MOM_restart, only : restart_init, restore_state, MOM_restart_CS
-use MOM_time_manager, only : time_type, set_time, time_type_to_real
+use MOM_time_manager, only : time_type, time_type_to_real, time_type_to_real, real_to_time
 use MOM_transcribe_grid, only : copy_dyngrid_to_MOM_grid, copy_MOM_grid_to_dyngrid
 use MOM_variables, only : surface
 use MOM_forcing_type, only : forcing, allocate_forcing_type, MOM_forcing_chksum
@@ -47,7 +47,7 @@ module MOM_ice_shelf
 use MOM_checksums, only : hchksum, qchksum, chksum, uchksum, vchksum, uvchksum
 use time_interp_external_mod, only : init_external_field, time_interp_external
 use time_interp_external_mod, only : time_interp_external_init
-use time_manager_mod, only : print_time, time_type_to_real, real_to_time_type
+use time_manager_mod, only : print_time
 implicit none ; private
 
 #include <MOM_memory.h>
@@ -979,7 +979,7 @@ subroutine add_shelf_flux(G, CS, state, fluxes)
 
       ! just compute changes in mass after first time step
       if (t0>0.0) then
-        Time0 = real_to_time_type(t0)
+        Time0 = real_to_time(t0)
         last_hmask(:,:) = ISS%hmask(:,:) ; last_area_shelf_h(:,:) = ISS%area_shelf_h(:,:)
         call time_interp_external(CS%id_read_mass, Time0, last_mass_shelf)
         last_h_shelf = last_mass_shelf/CS%density_ice