diff --git a/cicecore/cicedyn/infrastructure/io/io_netcdf/ice_history_write.F90 b/cicecore/cicedyn/infrastructure/io/io_netcdf/ice_history_write.F90
index 019ab8ce9..d85ec5e3c 100644
--- a/cicecore/cicedyn/infrastructure/io/io_netcdf/ice_history_write.F90
+++ b/cicecore/cicedyn/infrastructure/io/io_netcdf/ice_history_write.F90
@@ -48,7 +48,7 @@ subroutine ice_write_hist (ns)
       use ice_blocks, only: nx_block, ny_block
       use ice_broadcast, only: broadcast_scalar
       use ice_calendar, only: msec, timesecs, idate, idate0, write_ic, &
-          histfreq, days_per_year, use_leap_years, dayyr, &
+          histfreq, histfreq_n, days_per_year, use_leap_years, dayyr, &
           hh_init, mm_init, ss_init
       use ice_communicate, only: my_task, master_task
       use ice_domain, only: distrb_info
@@ -86,6 +86,7 @@ subroutine ice_write_hist (ns)
       integer (kind=int_kind), dimension(6) :: dimidex
       real (kind=dbl_kind)  :: ltime2
       character (char_len) :: title
+      character (char_len) :: time_period_freq = 'none'
       character (char_len_long) :: ncfile(max_nstrm)
       real (kind=dbl_kind)  :: secday, rad_to_deg
 
@@ -682,6 +683,25 @@ subroutine ice_write_hist (ns)
         if (status /= nf90_noerr) call abort_ice(subname// &
                       'ERROR: global attribute date2')
 
+        select case (histfreq(ns))
+         case ("y", "Y")
+            write(time_period_freq,'(a,i0)') 'year_',histfreq_n(ns)
+         case ("m", "M")
+            write(time_period_freq,'(a,i0)') 'month_',histfreq_n(ns)
+         case ("d", "D")
+            write(time_period_freq,'(a,i0)') 'day_',histfreq_n(ns)
+         case ("h", "H")
+            write(time_period_freq,'(a,i0)') 'hour_',histfreq_n(ns)
+         case ("1")
+            write(time_period_freq,'(a,i0)') 'step_',histfreq_n(ns)
+        end select
+
+        if (.not.write_ic .and. trim(time_period_freq) /= 'none') then
+           status = nf90_put_att(ncid,nf90_global,'time_period_freq',trim(time_period_freq))
+           if (status /= nf90_noerr) call abort_ice(subname// &
+                         'ERROR: global attribute time_period_freq')
+        endif
+
         title = 'CF-1.0'
         status =  &
              nf90_put_att(ncid,nf90_global,'conventions',title)
diff --git a/cicecore/cicedyn/infrastructure/io/io_pio2/ice_history_write.F90 b/cicecore/cicedyn/infrastructure/io/io_pio2/ice_history_write.F90
index 6407d8c76..a697a98d5 100644
--- a/cicecore/cicedyn/infrastructure/io/io_pio2/ice_history_write.F90
+++ b/cicecore/cicedyn/infrastructure/io/io_pio2/ice_history_write.F90
@@ -76,6 +76,7 @@ subroutine ice_write_hist (ns)
       integer (kind=int_kind), dimension(6) :: dimidex
       real (kind= dbl_kind) :: ltime2
       character (char_len) :: title
+      character (char_len) :: time_period_freq = 'none'
       character (char_len_long) :: ncfile(max_nstrm)
       integer (kind=int_kind) :: iotype
 
@@ -649,6 +650,23 @@ subroutine ice_write_hist (ns)
         write(title,'(a,i6)') 'seconds elapsed into model date: ',msec
         status = pio_put_att(File,pio_global,'comment3',trim(title))
 
+        select case (histfreq(ns))
+         case ("y", "Y")
+            write(time_period_freq,'(a,i0)') 'year_',histfreq_n(ns)
+         case ("m", "M")
+            write(time_period_freq,'(a,i0)') 'month_',histfreq_n(ns)
+         case ("d", "D")
+            write(time_period_freq,'(a,i0)') 'day_',histfreq_n(ns)
+         case ("h", "H")
+            write(time_period_freq,'(a,i0)') 'hour_',histfreq_n(ns)
+         case ("1")
+            write(time_period_freq,'(a,i0)') 'step_',histfreq_n(ns)
+        end select
+
+        if (.not.write_ic .and. trim(time_period_freq) /= 'none') then
+           status = pio_put_att(File,pio_global,'time_period_freq',trim(time_period_freq))
+        endif
+
         title = 'CF-1.0'
         status =  &
              pio_put_att(File,pio_global,'conventions',trim(title))