时 (traditional 時) = 日 (sun) + 寺/寸. Time was first told by the sun, so the sun radical anchors it. 时 means time, hour, season, a moment.
时 is one of the most common characters in Chinese because time-words are everywhere: 小时 (an hour, 'small-time' — pairs with 小, which you know), 时间 (time/duration), 几时 (when, 'what time'), 有时 (sometimes), 那时 (back then). Don't confuse 小时 (a duration, 'an hour') with 点 (a clock reading, 'o'clock') — 三个小时 is 'three hours long', 三点 is '3 o'clock'.
The sun (日) marking the hour — TIME.
Mind the difference: 点 is a clock reading (三点 = 3 o'clock), but 小时 is a duration (三个小时 = three hours long). Both are 'time', used differently.