I've created a simple real-time workflow which prepends the 'Modified on' and 'Modified by' fields to a multi-line string field every time a User makes a change to a Case record. (It's a simple alternative I created to using Auditing.) Most of the time it works fine but every now and again we'll see the 'Modified on' field that was recorded be several hours into the future. A few minutes/hours later when a user makes another change, the date & time will be correct.
Does anyone have any ideas of what is going on here?