Be flexible for the format inside Time class

[peter279k]

Is your feature request related to a problem? Please describe. I get started to think about the date format inside Time class.

It looks like the date format has the fixed format and developer doesn't have any option to make the date be formatted.

Such as Time::timestampToGmt result will be the d/m/Y H:i:s format.

Describe the solution you'd like Perhaps we consider have the option to define the date format string.

Possible approach I suggest the following approach and we should follow this rule.

• Add setDateFormat and getDateFormat methods and define private/protected dateFormat variable.
• Add the validateDateFormat method when setting setDateFormat.