1. A method comprising: (a) determining, by a processor, whether there is sufficient information that has been acquired so far about a current time period to perform similarity measurements; (b) in response to determining that there is not sufficient information that has been acquired so far about the current time period to perform similarity measurements, operating in a first mode in which the processor selects a reference set of profiles from a source set of profiles, using a plurality of initial selection rules; (c) in response to determining that there is sufficient information that has been acquired so far about the current time period to perform similarity measurements, operating in a second mode in which the processor selects the reference set of profiles by, for each previous profile of one or more previous profiles indicative of prior time periods, obtaining a similarity measurement through the comparison, by the processor, a current partial profile indicative of the information acquired so far about the current time period to the previous profile; where the similarity measurement denotes low dissimilarity between the current partial profile and the previous profile, adding, by the processor, the previous profile to the reference set of profiles; where the similarity measurement denotes high dissimilarity between the current partial profile and the previous profile, removing, by the processor, the previous profile to the reference set of profiles if present; and, (d) thereafter, using, by the processor, the reference set of profiles and the current partial profile to generate a forecast, repeating (a), (b), and (c) one or more times before performing (d), such that the first mode is initially used to select the reference set of profiles until sufficient information has been acquired about the current period to perform similarity measurements, and such that the second mode is thereafter used to refine the reference set of profiles after sufficient information has been acquired about the current period to perform similarity measurements; and wherein the first mode is used to select the reference set of profiles in a rule-based manner where insufficient information has been acquired so far about the current time period to perform similarity measurements, and the second mode is used to select the reference set of profiles in a similarity measurement-based manner where sufficient information has been acquired so far about the current time period to perform similarity measurements.