diff --git a/sql/upgrades/100.sql b/sql/upgrades/100.sql
new file mode 100644
index 000000000..7fd6f88e4
--- /dev/null
+++ b/sql/upgrades/100.sql
@@ -0,0 +1,58 @@
+-- SWH DB schema upgrade
+-- from_version: 99
+-- to_version: 100
+-- description: update swh_visit_find_by_date and swh_occurrence_get_by to return sensible results
+
+insert into dbversion(version, release, description)
+      values(100, now(), 'Work In Progress');
+
+CREATE OR REPLACE FUNCTION swh_occurrence_get_by(origin_id bigint, branch_name bytea = NULL::bytea, "date" timestamp with time zone = NULL::timestamp with time zone) RETURNS SETOF occurrence_history
+    LANGUAGE plpgsql
+    AS $$
+declare
+    filters text[] := array[] :: text[];  -- AND-clauses used to filter content
+    visit_id bigint;
+    q text;
+begin
+    if origin_id is null then
+        raise exception 'Needs an origin_id to get an occurrence.';
+    end if;
+    filters := filters || format('origin = %L', origin_id);
+    if branch_name is not null then
+        filters := filters || format('branch = %L', branch_name);
+    end if;
+    if date is not null then
+        select visit from swh_visit_find_by_date(origin_id, date) into visit_id;
+    else
+        select visit from origin_visit where origin = origin_id order by origin_visit.date desc limit 1 into visit_id;
+    end if;
+    if visit_id is null then
+        return;
+    end if;
+    filters := filters || format('%L = any(visits)', visit_id);
+
+    q = format('select * from occurrence_history where %s',
+               array_to_string(filters, ' and '));
+    return query execute q;
+end
+$$;
+
+CREATE OR REPLACE FUNCTION swh_visit_find_by_date(origin bigint, visit_date timestamp with time zone = now()) RETURNS origin_visit
+    LANGUAGE sql STABLE
+    AS $$
+  with closest_two_visits as ((
+    select ov, (date - visit_date) as interval
+    from origin_visit ov
+    where ov.origin = origin
+          and ov.date >= visit_date
+    order by ov.date asc
+    limit 1
+  ) union (
+    select ov, (visit_date - date) as interval
+    from origin_visit ov
+    where ov.origin = origin
+          and ov.date < visit_date
+    order by ov.date desc
+    limit 1
+  )) select (ov).* from closest_two_visits order by interval limit 1
+$$;