In a "helper" column try (assuming ALL the values 4 digits ):

=TIME(LEFT(A1,2),RIGHT(A1,2),0)

If everything is OK, then copy and paste special==values in the "helper"
column and delete original.

HTH



"Rita_H" wrote:

I have a text file with times expressed as a numeric - eg 0510. I have a few
hundred lines of input each with this format repeated. I need to change 0510
to 05:10 - ie 10 past 5 in the morning, but when I select the appropriate
time format, it converts it to 00:00 instead of 05:10. Is this automation
possible, perhaps with a custom format or do I have to go through hundreds of
cells putting in a colon?