Tuesday carries Mars's significations in the older astrological literature: energy, courage, assertive action and, on the more difficult side of the same planet's nature, conflict, aggression and haste. Because Mars was read as one of the two malefic planets alongside Saturn, medieval and Renaissance astrological handbooks generally counsel caution around undertakings begun on a Tuesday that require patience or diplomacy, while favouring the day for anything that genuinely calls for boldness, physical exertion or a direct confrontation of an obstacle.
The pairing of planetary day and planetary hour, where a working matched to both was held to gain strength from the doubled attribution, made a Tuesday hour of Mars, falling twice in the daylight and twice at night across the twenty four hour cycle, the most concentrated window for operations specifically concerned with Mars's domain, whether that meant literal martial activity, competitive contests, or simply summoning the resolve to begin something difficult.
Sources A History of Western AstrologyNicholas Campion with Grimoires: A History of Magic BooksOwen Davies