A very late response, however for reference, a solution to your problem would be similar to the example I'm attaching. In this example, a timestamp in generated and converted to date/time. All of the fields are converted to an I8 except for the fractional seconds. That field is multiplied by 100 (2 decimal places) and then converted to an I8. Each value is cast to a string, and then concatinated. The cast process will create a the equivilent hex string.
Converting from hex string to timestamp is simplified if your string is an U8 or I8 (for time it should be the same thing since there shouldn't be negative time) because you can use string to byte array. The byte array will now each time value seperated in the same order of the string. Using the index array, and the date/time to seconds, you can bundle each element to create your timestamp. The seconds to date/time can be used with the bundle to fill in any missing fields. For example, if you timestamp only has hour:min:sec:hsec, you can still have todays date in your timestamp. Sorry I didn't see this post till now, however I hope this helps you in the future.
