MAPS="map_1 map_2 map_3 map_4 map_5 map_6 map_7"

for map in ${MAPS} ; do
    r.mapcalc --o expr="${map} = 1" 
    echo ${map} >> map_list.txt 
done

t.create type=strds temporaltype=absolute \
         output=precipitation_daily \
         title="Daily precipitation" \
         description="Test dataset with daily precipitation"

t.register -i type=rast input=precipitation_daily \
           file=map_list.txt start="2012-08-20" increment="1 days"

t.rast.list precipitation_daily

map_1   soeren  2012-09-03 00:00:00 2012-09-04 00:00:00
map_2   soeren  2012-09-04 00:00:00 2012-09-05 00:00:00
map_3   soeren  2012-09-05 00:00:00 2012-09-06 00:00:00
map_4   soeren  2012-09-06 00:00:00 2012-09-07 00:00:00
map_5   soeren  2012-09-07 00:00:00 2012-09-08 00:00:00
map_6   soeren  2012-09-08 00:00:00 2012-09-09 00:00:00
map_7   soeren  2012-09-09 00:00:00 2012-09-10 00:00:00

t.rast.export input=precipitation_daily output=precipitation_daily.tar.gz \
              compression=gzip
t.rast.import input=precipitation_daily.tar.gz output=new_precipitation_daily \
              base=new_map extrdir=/tmp
              
t.rast.list new_precipitation_daily

new_map_0   soeren  2012-09-03 00:00:00 2012-09-04 00:00:00
new_map_1   soeren  2012-09-04 00:00:00 2012-09-05 00:00:00
new_map_2   soeren  2012-09-05 00:00:00 2012-09-06 00:00:00
new_map_3   soeren  2012-09-06 00:00:00 2012-09-07 00:00:00
new_map_4   soeren  2012-09-07 00:00:00 2012-09-08 00:00:00
new_map_5   soeren  2012-09-08 00:00:00 2012-09-09 00:00:00
new_map_6   soeren  2012-09-09 00:00:00 2012-09-10 00:00:00