Goal setting literature suggests that individuals set their goals more frequently on temporal landmarks, e.g. the New Year’s day (known as the fresh start effect). What remains unclear is whether setting goals on temporal landmarks has also a positive impact on goal attainment. We investigated goal setting and attainment behaviours in the context of an information system dedicated for smoking cessation with design features to promote such behaviours. We collected data from almost 1 million unique users from 2015 to 2021 and studied the effects of goals set on temporal landmarks on goal attainment for two groups: (1) users in their first attempts; and (2) users who continuously set the same goal. The results show that setting goals on temporal landmarks have mostly a negative influence on goal attainment for the first group. However, for the second group, setting goals on temporal landmarks is largely positively correlated with goal attainment.