R.I. Gen. Laws § 17-1-7: Uniform deadlines.

Notwithstanding any other time specified for the filing of any paper or the doing of any act pursuant to this title, a uniform deadline of 4:00 p.m. is established; provided, that applications for emergency mail ballots must be received by 4:00 p.m. on the day prior to an election or primary. If any filing deadline falls on a Saturday, Sunday, or holiday, the deadline shall be construed to fall on the next subsequent business day; provided, that this does not apply to registration to vote thirty (30) days prior to an election or primary, or change of party designation thirty (30) days prior to an election or primary under the requirements of § 17-9.1-24.