Reason #1:
"The expressions ‘time, times and the dividing of time’, ‘42
months’, ‘1260 days’, and ‘70 weeks’, are very peculiar. They could have been expressed in literal language but instead they are given a symbolic flavor.
Notice, for example, that Luke 4:25 and James 5:17 refer to the period when there was no rain in the days of Elijah as ‘three years and six months’. This is the normal way of expressing time (see also, Acts 18:11; II Samuel 2:11; I Samuel 27:7).
--It is significant that every measurement of time in prophecy is given a symbolic flavor:
hour (Revelation 17:12; 9:13),
day (Revelation 12:6),
week (Daniel 9:24-27),
month (Revelation 13:5),
year (Daniel 7:25).
--It is also significant that non-apocalyptic prophecies express time in literal language:
70 years (Jeremiah 25:11-12),
400 years (Genesis 15:13-15),
120 years (Genesis 6:3) with literal persons performing literal actions!" SecretsUnsealed
Unto two thousand and three hundred days;
then shall the sanctuary be cleansed.
Daniel 8:14