diff --git a/sheetsync/sheetsync/main.py b/sheetsync/sheetsync/main.py
index 5820135..71de7fb 100644
--- a/sheetsync/sheetsync/main.py
+++ b/sheetsync/sheetsync/main.py
@@ -193,16 +193,16 @@ class SheetSync(object):
 			query(self.conn, built_query, **row)
 			rows_found.labels(worksheet).inc()
 			rows_changed.labels('insert', worksheet).inc()
-			self.middleware.mark_modified(worksheet)
+			self.middleware.mark_modified(row)
 			return
 
 		if row is None:
 			assert event
 			if not self.create_missing_ids:
-				logging.info("Skipping event {} without any matching row".format(event["id"]))
+				logging.info("Skipping event {} without any matching row".format(event.id))
 				return
-			logging.info("Adding new row {}".format(event["id"]))
-			row = self.middleware.create_row(event["sheet_name"], event["id"])
+			logging.info("Adding new row {}".format(event.id))
+			row = self.middleware.create_row(event.sheet_name, event.id)
 
 		worksheet = row["sheet_name"]
 		rows_found.labels(worksheet).inc()
diff --git a/sheetsync/sheetsync/sheets.py b/sheetsync/sheetsync/sheets.py
index a9298f5..391fc64 100644
--- a/sheetsync/sheetsync/sheets.py
+++ b/sheetsync/sheetsync/sheets.py
@@ -90,6 +90,7 @@ class SheetsMiddleware():
 		self.sheet_id = sheet_id
 		# map {worksheet: last modify time}
 		self.worksheets = {w: 0 for w in worksheets}
+		self.bustime_start = bustime_start
 		self.edit_url = edit_url
 		self.allocate_ids = allocate_ids
 		# Maps DB column names (or general identifier, for non-DB columns) to sheet column indexes.
@@ -161,7 +162,7 @@ class SheetsMiddleware():
 		# Clear previously seen unassigned rows
 		self.unassigned_rows = {}
 		for worksheet in self.pick_worksheets():
-			rows = self.sheets.get_rows(self.sheet_id, worksheet)
+			rows = self.client.get_rows(self.sheet_id, worksheet)
 			for row_index, row in enumerate(rows):
 				# Skip first row (ie. the column titles).
 				# Need to do it inside the loop and not eg. use rows[1:],
@@ -172,10 +173,8 @@ class SheetsMiddleware():
 
 				# Handle rows without an allocated id
 				if row['id'] is None:
-					# If a row is all empty (including no id), ignore it and mark it down for possible use in create_row().
-					# Ignore the tags column for this check since it is never non-empty due to implicit tags
-					# (and even if there's other tags, we don't care if there's nothing else in the row).
-					if not any(row[col] for col in self.input_columns if col != 'tags'):
+					# Only assign a row an id if it has a start time and a description
+					if not any(row[col] for col in ["event_start", "description"]):
 						self.unassigned_rows.setdefault(worksheet, []).append(row["index"])
 						continue
 					# If we can't allocate ids, warn and ignore.
@@ -202,7 +201,7 @@ class SheetsMiddleware():
 				yield row
 
 	def write_id(self, row):
-		self.sheets.write_value(
+		self.client.write_value(
 			self.sheet_id, row["sheet_name"],
 			row["index"], self.column_map['id'],
 			str(row['id']),