The document discusses various time-based trend calculation methods used in technical analysis including: - Momentum, which measures price changes over time to identify trends. - Moving averages, which smooth price data by calculating average prices over a set time period to filter out noise. - Accumulative and reset accumulative averages, which calculate averages over all or reset periods of data. - The drop-off effect, where simple moving averages are affected when oldest data values are removed from the calculation.