diff --git a/kingfisher_scrapy/base_spider.py b/kingfisher_scrapy/base_spider.py
index a3aa62c7..badf778d 100644
--- a/kingfisher_scrapy/base_spider.py
+++ b/kingfisher_scrapy/base_spider.py
@@ -42,7 +42,7 @@ class BaseSpider(scrapy.Spider):
 
     MAX_SAMPLE = 10
     MAX_RELEASES_PER_PACKAGE = 100
-    VALID_DATE_FORMATS = {'date': '%Y-%m-%d', 'datetime': '%Y-%m-%dT%H:%M:%S'}
+    VALID_DATE_FORMATS = {'date': '%Y-%m-%d', 'datetime': '%Y-%m-%dT%H:%M:%S', 'year-month': '%Y-%m'}
 
     def __init__(self, sample=None, note=None, from_date=None, until_date=None,
                  date_format='date', *args, **kwargs):
diff --git a/kingfisher_scrapy/spiders/uruguay_base.py b/kingfisher_scrapy/spiders/uruguay_base.py
index d554fe89..168708d7 100644
--- a/kingfisher_scrapy/spiders/uruguay_base.py
+++ b/kingfisher_scrapy/spiders/uruguay_base.py
@@ -1,19 +1,22 @@
-from datetime import date
-
 from kingfisher_scrapy.base_spider import SimpleSpider
 from kingfisher_scrapy.util import components, date_range_by_month
 
 
 class UruguayBase(SimpleSpider):
     download_delay = 0.9
+    default_from_date = '2017-11'
+
+    @classmethod
+    def from_crawler(cls, crawler, from_date=None, *args, **kwargs):
+        if not from_date:
+            from_date = cls.default_from_date
+
+        return super().from_crawler(crawler, date_format='year-month', from_date=from_date, *args, **kwargs)
 
     def start_requests(self):
         url = 'http://comprasestatales.gub.uy/ocds/rss/{0.year:d}/{0.month:02d}'
-
-        start = date(2017, 11, 1)
-        stop = date.today().replace(day=1)
         if self.sample:
-            start = stop
+            self.from_date = self.until_date
 
-        for d in date_range_by_month(start, stop):
+        for d in date_range_by_month(self.from_date, self.until_date):
             yield self.build_request(url.format(d), formatter=components(-2), callback=self.parse_list)