How long is the timeline for promotion from 2LT to 1LT in the National Guard?

I read that the more you salute 1LTs the faster you will get promoted.

Promotion to 1LT is pretty much automatic. It will take 24 months but it is waiverable to 18. I got mine in 18 months. Also, this is the only rank were they can back date your date of rank. When you get your FEDREC it will be for the day you first became eligible. I was promoted in April but my date of rank on my official orders were for Feb. So I got that back pay. After that it is much more difficult.

Mcquaid, some states take longer than others. I finished BOLC last year and got my state promotion orders in March (still a month after our promo date). My packet is still sitting at JAG according to the FEDREC Tracker. 7 months in since I received my promotion and I'm still waiting. Haha. Best of luck brother! Just gotta wait it out.