Converting Numeric Values to Times

Sam has a lot of worksheets that contain times. The problem is that the times are in the format "1300" instead of the format "13:00." Thus, Excel sees them as regular numeric values instead of recognizing them as times. Sam wants them to be converted to actual time values.

There are several ways you can approach this task. One way is to use the TIME function to convert the value to a time, as shown here:

=TIME(LEFT(A1,2),RIGHT(A1,2),)

This formula assumes that the time in cell A1 will always contain four digits. If it does not (for instance, it might be 427 instead of 0427), then the formula needs to be modified slightly:

=TIME(LEFT(A1,LEN(A1)-2),RIGHT(A1,2),)

The formula basically pulls the leftmost digit (or digits) and uses them for the hours argument of the TIME function, and then uses the two rightmost digits for the minutes argument. TIME returns an actual time value, formatted as such in the cell.

A similar formulaic approach can be taken using the TIMEVALUE function:

=TIMEVALUE(REPLACE(A1,LEN(A1)-1,0,":"))

This formula uses REPLACE to insert a colon in the proper place, and then TIMEVALUE converts the result into a time value. You will need to format the resulting cell so that it displays the time as you want.

Another variation on the formulaic approach is to use the TEXT function, in this manner:

=--TEXT(A1,"00\:00")

This returns an actual time value, which you will then need to format properly to be displayed as a time.

Another approach is to simply do the math on the original time to convert it to a time value used by Excel. This is easy once you realize that time values are nothing more than a factional part of a day. Thus, a time value is a number between 0 and 1, derived by dividing the hours by 24 (the hours in a day) and the minutes by 1440 (the minutes in a day). Here is a formula that does that:

=INT(A1/100)/24+MOD(A1,100)/1440

This determines the hour portion of the original value, which is then divided by 24. The minute portion (the part left over from the original value) is then divided by 1440 and added to the first part. You can then format the result as a time, and it works perfectly.

All of the formulas described so far utilize a new column in order to do the conversions. This is handy, but you may want to actually convert the value in-place, without the need for a formula. This is where a macro can come in handy. The follow macro will convert whatever cells you have selected into time values and format the cells appropriately:

Sub NumberToTime()
    Dim rCell As Range
    Dim iHours As Integer
    Dim iMins As Integer

    For Each rCell In Selection
        If IsNumeric(rCell.Value) And Len(rCell.Value) > 0 Then
            iHours = rCell.Value \ 100
            iMins = rCell.Value Mod 100
            rCell.Value = (iHours + iMins / 60) / 24
            rCell.NumberFormat = "h:mm AM/PM"
        End If
    Next
End Sub

The macro uses an integer division to determine the number of hours (iHours) and stuffs the remainder into iMins. This is then adjusted into a time value and placed back into the cell, which is then formatted as a time. You can change the cell format, if desired, to any of the other time formats supported by Excel.