BY A STAFF REPORTER: Tomorrow, Sunday, July 31 is the last date for filing income tax returns. And today, on Saturday, the filing of file returns fell apart. If you do not file income tax return within the stipulated day, you may get a big penalty. And today, till 6 pm on Saturday, 35 lakh 67 thousand 263 income tax return files have been filed. In the last one hour, 4,48,000 income tax return files have been filed.