There is no way to know which day Steritech will come. My ETLs always say "This store in our district had their visit yesterday so we'll probably have our visit today!" and then we don't have a visit for 3 or 4 weeks... They've mostly stopped saying that, now that I've told them how much bullshit it is. Unless the Steritech person knew their schedule and told that store, but that seems really sketchy...
However, you should always be ready for Steritech to drop in at any moment. I've been meaning to type up a Steritech guide for my team, so maybe this will get me started, along with the help of the other SBTLs.
Mops must not be touching the sink/floor; they must be hung or inverted. Everything needs to be labeled/dated. No expired stuff. Sanitizer should be between 65*-85* and 200ppm-400ppm. Sanitizer spray bottles should be labeled with today's date. Buckets, pitchers, etc should be inverted (so they don't get dust or splashes of anything on the part that will be in contact with food). Watch for dust build up on pretty much everything - even the ceiling vents/lights! Wipe down the inside of the ice machine - especially the black plastic thing that the ice hits as it falls down. Make sure you only have approved cleaning supplies/chemicals. Know the process to clean pretty much anything - wash, rinse, sanitize, and air dry. Make sure all temperatures have been taken and that you have LOD signatures where it is required. No evidence of pests (insects/rodents); if there are, there needs to be a workorder in for it (note: vendors don't do ANYTHING to help...). You can't have anything at the handwashing sinks except the required things (soap, paper towels, maybe hand sanitizer for Pizza Hut areas). Follow the dress code - wear a hat, no jewelry except like a wedding band and maybe a medical bracelet. If you have a wound on your hand, wear one of those blue bandaids (and gloves if you're touching food).
This list is non-exhaustive.