diff --git a/seaice_ecdr/cli/nrt.py b/seaice_ecdr/cli/nrt.py
index 2060cfe5..6e8cb062 100644
--- a/seaice_ecdr/cli/nrt.py
+++ b/seaice_ecdr/cli/nrt.py
@@ -7,12 +7,13 @@
 import copy
 import datetime as dt
 from pathlib import Path
-from typing import get_args
+from typing import Literal, get_args
 
 import click
+from loguru import logger
 from pm_tb_data._types import Hemisphere
 
-from seaice_ecdr.cli.util import CLI_EXE_PATH, datetime_to_date, run_cmd
+from seaice_ecdr.cli.util import CLI_EXE_PATH, run_cmd
 from seaice_ecdr.constants import DEFAULT_BASE_NRT_OUTPUT_DIR
 from seaice_ecdr.platforms.config import NRT_PLATFORM_START_DATES_CONFIG_FILEPATH
 
@@ -21,9 +22,11 @@
 @click.option(
     "-d",
     "--date",
-    required=True,
+    "--start-date",
+    required=False,
+    default=None,
     type=click.DateTime(formats=("%Y-%m-%d", "%Y%m%d", "%Y.%m.%d")),
-    callback=datetime_to_date,
+    callback=lambda _ctx, _param, value: value if value is None else value.date(),
 )
 @click.option(
     "--end-date",
@@ -40,11 +43,18 @@
     default=None,
     help="If given, run temporal composite for `--date` through this end date.",
 )
+@click.option(
+    "--last-n-days",
+    required=False,
+    type=click.INT,
+    default=None,
+    help="If given, run temporal composite for the last n dates.",
+)
 @click.option(
     "-h",
     "--hemisphere",
     required=True,
-    type=click.Choice(get_args(Hemisphere)),
+    type=click.Choice([*get_args(Hemisphere), "both"]),
 )
 @click.option(
     "--base-output-dir",
@@ -72,22 +82,43 @@
 )
 def cli(
     *,
-    date: dt.date,
+    date: dt.date | None,
     end_date: dt.date | None,
-    hemisphere: Hemisphere,
+    last_n_days: int | None,
+    hemisphere: Hemisphere | Literal["both"],
     base_output_dir: Path,
     overwrite: bool,
 ):
+
+    if last_n_days and (date or end_date):
+        raise RuntimeError(
+            "`--last-n-days` is incompatible with `--date` and `--end-date`"
+        )
+
+    if last_n_days:
+        date = dt.date.today() - dt.timedelta(days=last_n_days)
+        # The end date should be the day before today. We only expect today's
+        # data to be available on the following day.
+        end_date = dt.date.today() - dt.timedelta(days=1)
+
     if end_date is None:
         end_date = copy.copy(date)
 
+    logger.info(f"Creating NRT data for {date} through {end_date}")
+
     overwrite_str = " --overwrite" if overwrite else ""
 
-    run_cmd(
-        f"export PLATFORM_START_DATES_CONFIG_FILEPATH={NRT_PLATFORM_START_DATES_CONFIG_FILEPATH} &&"
-        f"{CLI_EXE_PATH} nrt"
-        f" --hemisphere {hemisphere}"
-        f" --base-output-dir {base_output_dir}"
-        f" --date {date:%Y-%m-%d}"
-        f" --end-date {end_date:%Y-%m-%d}" + overwrite_str
-    )
+    if hemisphere == "both":
+        hemispheres = ["north", "south"]
+    else:
+        hemispheres = [hemisphere]
+
+    for hemi in hemispheres:
+        run_cmd(
+            f"export PLATFORM_START_DATES_CONFIG_FILEPATH={NRT_PLATFORM_START_DATES_CONFIG_FILEPATH} &&"
+            f"{CLI_EXE_PATH} nrt"
+            f" --hemisphere {hemi}"
+            f" --base-output-dir {base_output_dir}"
+            f" --date {date:%Y-%m-%d}"
+            f" --end-date {end_date:%Y-%m-%d}" + overwrite_str
+        )