Does this do it?
I'm assuming that you know the ranges and that you don't want the formula to identify those for you but only to do the calculation - perhaps that isn't right....
Assumes that all dates in A are in the same month
Formula in a9 is an array formula to be entered with CTRL+SHIFT+ENTER
=((EOMONTH(A2,0)+1)*SUM(B2:B6)-SUM(A2:A6*B2:B6))/DAY(EOMONTH(A2,0))
EOMONTH requires Analysis ToolPak
******** ******************** ************************************************************************><center><table align="center" cellpadding="0" cellspacing="0"><tbody><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0);" colspan="5" bgcolor="#0c266b"><table width="100%" align="center" border="0"><tbody><tr><td align="left">
Microsoft Excel - days&months.xls</td><td style="font-size: 9pt; color: rgb(255, 255, 255); font-family: caption;" align="right">___Running: 11.0 : OS = Windows XP </td></tr></tbody></table></td></tr><tr><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); height: 25px;" colspan="5" bgcolor="#d4d0c8"><table valign="MIDDLE" width="100%" align="center" border="0"><tbody><tr><td style="font-size: 10pt; color: rgb(0, 0, 0); font-family: caption;">(
F)ile (
E)dit (
V)iew (
I)nsert (
O)ptions (
T)ools (
D)ata (
W)indow (
H)elp
(A)bout</td><td valign="center" align="right"><form name="formCb059465"><input *******="window.clipboardData.setData("Text",document.formFb543420.sltNb142651.value);" value="Copy Formula" name="btCb290334" type="button"></form></td></tr></tbody></table></td></tr><tr><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0);" colspan="5" bgcolor="white"><table border="0"><tbody><tr><form name="formFb543420"></form><td style="width: 60px;" align="middle" bgcolor="white"><select onchange="document.formFb543420.txbFb965317.value = document.formFb543420.sltNb142651.value" name="sltNb142651"><option value="{=((EOMONTH(A2,0)+1)*SUM(B2:B6)-SUM(A2:A6*B2:B6))/DAY(EOMONTH(A2,0))}" selected="selected">A9</option></select></td><td width="3%" align="right" bgcolor="#d4d0c8">
=</td><td align="left" bgcolor="white"><input size="80" value="{=((EOMONTH(A2,0)+1)*SUM(B2:B6)-SUM(A2:A6*B2:B6))/DAY(EOMONTH(A2,0))}" name="txbFb965317"></td></tr></tbody></table></td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); background-color: rgb(212, 208, 200);" width="2%" align="middle">
</td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: black; font-family: menu; background-color: rgb(212, 208, 200);" align="middle"><center>A</center></td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: black; font-family: menu; background-color: rgb(212, 208, 200);" align="middle"><center>B</center></td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: black; font-family: menu; background-color: rgb(212, 208, 200);" align="middle"><center>C</center></td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: black; font-family: menu; background-color: rgb(212, 208, 200);" align="middle"><center>D</center></td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>1</center></td><td style="border-style: solid; border-color: rgb(0, 0, 0) rgb(212, 208, 200) rgb(212, 208, 200) rgb(0, 0, 0); border-width: 0.5pt; font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>2</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">01/01/2005</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">10</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>3</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">05/01/2005</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">1</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>4</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">10/01/2005</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">4.65</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>5</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">18/01/2005</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">7</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>6</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">22/01/2005</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">20</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>7</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>8</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>9</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
23.78</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-top: 0.5pt solid rgb(0, 0, 0); border-left: 0.5pt solid rgb(0, 0, 0); font-size: 10pt; color: rgb(0, 0, 0); font-family: menu; background-color: rgb(212, 208, 200);" width="2%" align="middle"><center>10</center></td><td style="border-left: 0.5pt solid rgb(0, 0, 0); border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(212, 208, 200); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td><td style="border-right: 0.5pt solid rgb(0, 0, 0); border-bottom: 0.5pt solid rgb(212, 208, 200); font-size: 10pt; vertical-align: bottom; color: rgb(0, 0, 0); font-family: Arial; background-color: rgb(255, 255, 255); text-align: right;">
</td></tr><tr><td style="border-style: solid; border-color: rgb(128, 128, 128) rgb(0, 0, 0) rgb(0, 0, 0); border-width: 0.5pt; background-color: rgb(212, 208, 200);" colspan="5"><table valign="TOP" width="100%" align="left"><tbody><tr><td style="border-style: solid; border-color: rgb(128, 128, 128) rgb(0, 0, 0) rgb(0, 0, 0); border-width: 0.5pt; width: 120pt; background-color: rgb(255, 255, 255);" align="left">
Sheet3</td><td>
</td></tr></tbody></table></td></tr></tbody></table>
[HtmlMaker 2.42] To see the formula in the cells just click on the cells hyperlink or click the Name box
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