One evening plus one morning equals one day. 2,300 evenings and mornings is the same as 1,150 mornings plus 1,150 evenings, which is the same as 1,150 days.
One problem with your interpretation. There's an evening and a morning, but there is no afternoon. So, here's another way to look at it. One evening-morning is therefore 18/24 hours = ¾ of a day. 2300 evening-morning x ¾ = 1725 days:
Vision of the 2,300 evening-morning: The small horn/fierce king[1] is to act arrogantly against the Prince of the army,[2] from whom the continuity is to be removed and whose sanctuary is to be thrown down (v. 11).[3] An army is defeated and the continuity disrupted (v. 12)[4] because of cooperation between the small horn/fierce king (vv. 9, 23) and the transgression causing desolation (v. 13).[5] Only after 2,300 evening-morning time units[6] (v. 14a, 26) will the holy place or sanctuary be restored to its rightful state, meaning the leadership of God’s people will be reinstated and true worship re-established (v. 14b).[7]
[1] These represent the Anglo-American world power, later identified as King of the South (cf. Dan. 8:9, 10, 19; 11:27-40). Again, the described course of events is from the perspective of King of the South (Dan. 11:40; cf. Rev. 13:11-13). As master of intrigue he will be removing the constant feature by cunning legal strategy, shrewdness and deception (Dan. 8:23-25; cf. Ps. 94:20).
[2] This means he will be taking on the Prince of the army, Jesus Christ himself. There can only be one outcome (Rev. 16:14, 16; 19:11-21; cf. Dan 8:25).
[3] Constant [feature]: The continuity (BDBLex) or regular offering (HALOT) here means the good deeds of God’s people during the Tribulation period (Rom. 10:10-15; cf. Hebr. 13:10-16). The sanctuary means the leaders of God’s people. Their freedom will be curtailed and their good works and holy sacrifices will be trampled upon (1 Cor. 3:16, 17; Eph. 2:21, 22; 1 Pet. 2:5-9; cf. Rev. 11:2).
[4] This is God’s army of evangelizers bringing the good news of the Messianic kingdom to the nations (cf. Ps. 68:11; 110:3). God temporarily abandons the army and sanctuary because of transgression, allowing them to be overrun by those who oppose true worship.
[5] This corrupt entity, the UN, is a transgressor of cultic law, thus God’s Law (HALOT). The transgression causing desolation lives up to its name, causing physical and spiritual ruin (Rev. 13:16, 17; 14:9-11; cf. Dan. 8:12; Is. 24:19, 20; 59:12-15; Lam. 3:8, 9, 42-45). In the near future all such corrupting influences are to be removed along with the transgressors (Dan. 8:13, 23; Rev. 17:13, 14; 19:11-21; cf. Dan. 9:24).
[6] Evening-morning: 1) The two nouns are singular. 2) Lit. an “evening-morning” time unit (not time, year or day), resulting in a most unusual time scale. 3) Evening in Hebrew means when the sun goes down. Morning means first light, when the sun comes up, until midday when the sun is at its zenith. Afternoon, when the day starts to fade, is not part of the equation. 4) One evening-morning is therefore 18/24 hours = ¾ of a day. 2300 evening-morning x ¾ = 1725 days. This literal interpretation does not deviate from Hebrew usage (Ex. 12:6, 10; 16:8-13; 27:21a; cf. 1 Kings 17:6).
[7] Then the sanctuary will be cleansed (NKJ) or reconsecrated (NIV) according to Ezek. 43. After having been trampled by the nations, those taking the lead in true worship of the Almighty God will be reinstated.