VisualMvo and MvoPlus 1.x do not have any internal notion of dates as such, just periods. The period may be designated as monthly, quarterly or annual, but this designation is for informational purposes only, and does not affect the working of the programs.
Any given data set must use a fixed period; there is no provision for converting returns between different periods. The periods themselves must be labelled by consecutive integers, and this labelling is under the complete control of the user. For example, the user might label 5 years of monthly data as periods 1 though 60. For annual data it is recommended that 4-digit years be used, though this is not actually required if both the beginning and end year are in the same century.
No internal truncation of the period labels is performed by the programs.
MCRetire 1.x does not use dates.