re = /(\d{2}(\d{2})?\/\d{2}\/\d{2}(\d{2})?)|(\d{2}:\d{2}(:\d{2})?)/
str = 'Log Started
Created Date: 01/01/01 Time: 01:01:01 Start
Added resources at module on 01/01/01 01:01
Module 2 excecute
Resource depleted at 01:01 n pieces
Open 01/01/01 01:01:01 Log to refer
Target end date of new resource 01/01/01 approved
Log Ended. Result OK'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html