Buying Train Reservations and Separate Tickets With Short Time on Eurail Site

You wait until the tickets are released for sale, when that happens varies but 3 months before is quite common. And for single tickets, the way to save fees is to buy them from the company that actually operates the train and avoid 3rd party ticket resellers.

You don't say what trips these "separate tickets for shorter trips" are for. Different rail companies have different ticketing policies. Some trips the tickets are train specific and come with reserved seats. Some trips there are no reservations possible, just get on the train. It is not even possible to buy tickets for some trips in advance, you just buy at the station on the day.
If it says it is too early to buy tickets, then you can't buy them.

It is usually cheaper and easier to buy direct from the company running the trains, not a reseller, many of which charge fees and only sell some tickets. Read this webpage for more info: https://www.seat61.com/Europe-train-tickets.htm

Yes I know about that. I searched and found a night train from Vienna to Venice with sleeper with wc/shower 2 beds, etc. for $298 but went to check on another ticket price for another trip. When I went back to purchase the night train ticket it said it was too early to buy. So it wasn't too early 30 minutes ago but now it is too early. Very weird!!!

Don't buy individual tickets from Eurail. Buy from the company operating the train. Eurail does not offer all trains available and quite often not the cheapest tickets. The sites may show the schedule for a future date but may not yet offer those tickets for sale.

who is running a countdown clock for purchase?

RailEurope

You should buy this ticket from the rail computer, not a reseller. Go to www.oebb.at to purchase tickets.

Yes I tried tha OBB site. I registered for an account and was told that I would receive an email to confirm my address, click on the link in the email, etc. but the email never came. Went back into the site and tried to register again and message said sorrow this email address already has an account but it would not let me sign in. Same crap as other sites.

Time to use the contact form and ask.
https://www.oebb.at/en/reiseplanung-services/kundenservice/kontakt.html

You do not need an account to buy tickets on the ÖBB website.

Is the e-mail perhaps in your spam?

Chris F - exactly what I was going to say!

Yes, the email was in my spam folder. I realized later that I did not need an account to purchase tickets; however, because the page that listed the ticket options and where to indicate the number of travelers was in German, I had difficulty reading it since I only know a little German used for travel. Part of the site can display English but could not get the order page to translate to English. I have some time since my wife will have to get a Schengen visa before we leave 2 Sept because she has a China passport and green card for US
Actually the price is about the same after converting euros to USD..

Update. Located the English version for ordering tickets but the price is a little more than on other sites and not refundable. Could not find a place to enter Global Pass information so the cost would probable be less. Have to wait for my wife's visa approval before I purchase a non-refundable ticket. Thanks for all the comments. Can close this conversation unless someone has more information.

I guess I don't understand. You say you are trying to buy "Separate Tickets" on the Eurail site, but the Eurail site does not sell individual tickets (reference). I think you mean the RailEurope site. RailEurope is a poor place from which to buy tickets. As mentioned above, they do not offer tickets for all trains, only the ones they want to sell you, usually the most expensive trains, and those tickets include their profit so are more expensive than buying the same tickets directly from the European railroad sites (German Rail, Austrian Rail, etc).

If you want to buy passholder sleeper reservations for the NightJet, then you can do that either through our Rail Europe link, including as part of a larger order, or by phone with OEBB (but not on their web site), or at a train station in Europe. Since you're interested in the deluxe double, you must be planning to purchase the 1st-class version of the pass. Do wait until it's no more than 90 days in advance of your travel date, and perhaps a little less. There's no special deal on rail passes at the moment, so presumably the whole purchase can wait.

Thanks for the information Lee. Yes, I did mean RailEuope not Eurail. I have had a lot of trouble with the RailEurope site but recently was able to book some seat reservations and short distance tickets at a good price. Discovered Trainline.com as a possible site for purchasing OBB. In fact was able to book Nightjet from Vienna to Venice with them when RailEurope said it was too early.

Laura, why do you say not to book with OBB online? I have an account set up with them. However as I mentioned above Trainline.com also books OBB night train tickets. The sleeper reservation was only in 2nd class though. No first class offered that I saw.
Are you saying that it is possible to use a 1st class rail pass like a Global Pass to use for Nightjet night train sleeper reservations?

Hi, Edward. My note about sleeper reservations for pass holders was based on the link that I provided there to OBB's price list and other information for pass holders. If you have now booked tickets through TrainLine.eu, then you probably have whole tickets, perhaps with advance-purchase discount, which won't require using a day of a rail pass. A rail pass covers the base price of train tickets, but not seat or sleeper reservation fees. Deluxe sleepers usually require a first-class ticket or pass.