It seems I remember seeing references to this being a "bad " placement in horary, yet some seem to use it as a secondary significator.
There are a number of "strictures," "warnings" and "considerations" in Horary.
None of them render a chart invalid. When Saturn is not a significator of the Querent or the Quesited/Matter, and it appears in the 1st House, it signifies the destruction of the Matter/Question when Saturn is Malefic.
If Saturn appears in the 1st House, and it is Exalted (in Libra) and Direct (and not Retrograde) and not impeded by a square or opposition from the Sun, a Malefic Mercury or from Mars, then it signifies great delays in the Matter being perfected, assuming the Matter will be perfected.
To discover the reason or cause of the delay, look to the Houses Saturn rules, Capricorn and Aquarius. Since Saturn is in Libra, an Air Sign, I would scrutinize Aquarius.
If Libra is the Ascendant, then Aquarius will be the 5th House Cusp, possibly the 6th House if Pisces is intercepted in the 6th House.
Remember the Planets signify both Things and People. So you're looking at Saturnian people and those things ruled by Saturn. While it is your 5th House, if the his a relationship or other 7th House Horary, it most likely would be the 11th House of the Quesited, meaning here that a friend of the Quesited will cause delays in perfecting the Matter.
If it would be a Matter of Substance, that is the 1st and 2nd Houses are used in delineation, then the 5th House would be the fourth House from the 2nd House, so your father or parents might interfere and delay whatever is happening, or it could be something else related to the fourth House significations.
If Aquarius fell on the 6th House, that is Illnesses and Servants, so perhaps an illness delays perfection of the Matter. It could also be your employees or people that work for you who delay the Matter. Again, in a 7th House issue, the 6th House is the 12th House of the Quesited, so it could be that secret enemies attempt to sabotage the plans resulting in delays, or that the Quesited has some fears to get over until those are overcome the Matter is delayed.
Then look at Capricorn. You'd want to see aspects. The mere fact that Saturn in the 1st with Aquarius on the 6th House Cusp doesn't mean you'd get an illness. If Venus was applying to Saturn it could (especially if Saturn did not receive Venus). If Mars were applying to Saturn that would indicate fear or secret enemies of the Quesited.
As far as how long a Matter will be delayed, that would depends on the difference in degrees between the significators and the Signs/Houses involved and then try to fumble your way through Zael's
On Times to get the timing.