 <p>This can be done using formulas by a two step approach:</p> <p>a) split the number (assuming it is in in cell <strong>A1</strong>) into pieces <code>=CONCATENATE(LEFT(A1;4);"-";MID(A1;5;2);"-";RIGHT(A1;2))</code> This gives you your date as a STRING in a cell.</p> <p>b) Combine this with VALUE, like <code>=VALUE(CONCATENATE(LEFT(A1;4);"-";MID(A1;5;2);"-";RIGHT(A1;2)))</code></p> <p>This yields to a date number <strong>41220</strong> (from start of counting, as determined by <code>Tools&gt;Options...&gt;OpenOffice.org Calc&gt;Calculate&gt;Date</code>; mine is set to option '1899-12-30'). Now format as you like.</p>