of polling stations. Voters receive poll cards informing them of the polling stations where they can cast their votes in person. Polling day at a general election is a public holiday, and voting is compulsory. Unless the returning officer decides otherwise, polling stations are open from 8:00 am to 8:00 pm on polling day. To vote, voters must go to the polling stations assigned to them. Applying for a ballot paper or voting in the name of someone else, or attempting to vote more than once, amounts to the offence of personation. If a person claiming to be a voter named in the electoral register turns up at a polling station after someone also claiming to be that voter has already voted, the second person is permitted to cast what is called a "tendered vote" using a ballot paper of a different colour after taking an oath to confirm his identity. Overseas voting Introduced in 2005 but not used until the 2006 elections, voters are also allowed to cast their votes aboard outside Singapore at any one of the ten designated overseas polling stations (those being Dubai, London, Tokyo, Beijing, Washington D.C., Hong Kong, Shanghai, San Francisco, New York and Canberra) in addition to the eligibilities as a local voter, an additional criteria for eligibility as an overseas voter is that the voter must provide both a recent contact address (Local Contact Address (LCA)) and an overseas address on the voter's residence registered with the Immigration & Checkpoints Authority (ICA), and has resided in Singapore for an aggregate of at least 30 days during the 3-year period before the cut-off date. Polling stations open based on the times from the Singapore time zone (UTC+08:00), from 8 am to 8 pm. Similar to votes cast locally, voting is also compulsory and can only be done once. After voting ended, the ballot boxes are sealed and are transported back to Singapore; the counting is conducted a few days after the election ended and once all the boxes are safely returned, though the counts of the votes do not affect the eventual outcome as the overseas electorate is much smaller, ranging from 558 during the debut to 6,570 in the recent 2020 election. Results After the poll closes, the presiding officer of each polling station seals the ballot boxes without opening them. Candidates or their polling agents may also affix their own seals