I set interval_seconds=21600 but ./wrf.exe outputs hourly

[Charlie]

Hi,

As per the subject, I set interval_seconds=21600 in both namelist.wps and namelist.input. Now, running ./metgrid.exe gave me the right intervals as shown below:
met_em.d01.2025-05-06_06:00:00.nc
met_em.d01.2025-05-06_12:00:00.nc
met_em.d01.2025-05-06_18:00:00.nc
met_em.d01.2025-05-07_00:00:00.nc
etc.
However, running ./wrf.exe gave me hourly files as shown below:
wrfout_d01_2025-05-06_00:00:00
wrfout_d01_2025-05-06_01:00:00
wrfout_d01_2025-05-06_02:00:00
wrfout_d01_2025-05-06_03:00:00
etc.
Where did I go wrong? Below are my namelist.wps and namelist.input respectively:

namelist.wps:

&share
wrf_core = 'ARW',
max_dom = 2,
start_date = '2025-05-06_00:00:00', '2025-05-06_00:00:00',
end_date = '2025-05-22_00:00:00', '2025-05-06_00:00:00',
interval_seconds = 21600,
io_form_geogrid = 2,
debug_level = 0,
/

&geogrid
parent_id = 1,1,
parent_grid_ratio = 1,3,
i_parent_start = 1,179,
j_parent_start = 1,50,
e_we = 350,292,
e_sn = 200,292,
geog_data_res = 'default','default',
dx = 15000,
dy = 15000,
map_proj = 'mercator',
ref_lat = -6.879,
ref_lon = 140.856,
truelat1 = -6.879,
truelat2 = 0,
stand_lon = 140.856,
geog_data_path = './WPS_GEOG',
/

&ungrib
out_format = 'WPS',
prefix = 'FILE',
/

&metgrid
fg_name = 'FILE',
io_form_metgrid = 2,
/

namelist.input:

&time_control
run_days = 0,
run_hours = 384,
run_minutes = 0,
run_seconds = 0,
start_year = 2025, 2025,
start_month = 05, 05,
start_day = 06, 06,
start_hour = 00, 00,
end_year = 2025, 2025,
end_month = 05, 05,
end_day = 22, 22,
end_hour = 00, 00,
interval_seconds = 21600,
input_from_file = .true.,.true.,
history_interval = 60, 60,
frames_per_outfile = 1, 1,
restart = .false.,
restart_interval = 7200,
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
/

&domains
time_step = 90,
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 2,
e_we = 350, 292,
e_sn = 200, 292,
e_vert = 45, 45,
dzstretch_s = 1.1
p_top_requested = 5000,
num_metgrid_levels = 34,
num_metgrid_soil_levels = 4,
dx = 15000,
dy = 15000,
grid_id = 1, 2,
parent_id = 1, 1,
i_parent_start = 1, 179,
j_parent_start = 1, 50,
parent_grid_ratio = 1, 3,
parent_time_step_ratio = 1, 3,
feedback = 1,
smooth_option = 0
/

&physics
physics_suite = 'CONUS'
mp_physics = -1, -1,
cu_physics = -1, -1,
ra_lw_physics = -1, -1,
ra_sw_physics = -1, -1,
bl_pbl_physics = -1, -1,
sf_sfclay_physics = -1, -1,
sf_surface_physics = -1, -1,
radt = 15, 15,
bldt = 0, 0,
cudt = 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0,
fractional_seaice = 1,
/

&fdda
/

&dynamics
hybrid_opt = 2,
w_damping = 0,
diff_opt = 2, 2,
km_opt = 4, 4,
diff_6th_opt = 0, 0,
diff_6th_factor = 0.12, 0.12,
base_temp = 290.
damp_opt = 3,
zdamp = 5000., 5000.,
dampcoef = 0.2, 0.2,
khdif = 0, 0,
kvdif = 0, 0,
non_hydrostatic = .true., .true.,
moist_adv_opt = 1, 1,
scalar_adv_opt = 1, 1,
gwd_opt = 1, 0,
/

&bdy_control
spec_bdy_width = 5,
specified = .true.
/

&grib2
/

&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/

Incidentally I am running WRF v4.4

 

[kwerner]

Hi,
This is happening because of the following two settings in namelist.input:

history_interval = 60, 60,
frames_per_outfile = 1, 1,

history_interval is the interval, in minutes, between the times history is written to the output. Since it's set to 60, it will write new history every hour.
frames_per_outfile is the number of history output times within each file. Since this is set to 1, a new file is written every history time - every hour since history_interval = 60.