I'm not a LOD, ETL or TL - but i know a good amount. As a SR TL at my store atleast, they always rotate closes between monday/friday.
Late- Get in and hand off with the Morning LOD (sometimes mid, especially on weekends) and take notes down. Call outs, notes, ops (opportunities to fix tomorrow morning), late, etc. Write the breakout (where closers zone, what time they take breaks). Sometimes the earlier hardlines TL will write the hardlines/electronics/beauty breakout, sometimes the soft lines one will too. If not, you can always hand that to the TLOD. Check your email, but not for too long. Your other leadership peers will get annoyed when your checking your email FOREVER when it takes just a little bit. Take LOD calls. Have a grid on you from the morning LOD or your own - near the end of the night you will walk the store while walking zones, and take notes of OPs. (opportunities to fix, such as an empty front endcap) ALWAYS be willing to backup, or when the GSTL/GSA calls for backup, MAKE SURE THEY GET BACKUP! call out your closers individually to go up there.
Mids- For my store, this is usually weekend only. Does not happen all the time, such as when the mid LOD usually has a vacation. Backup the morning LOD as much as possible, and help them out. You are the LOD too, so if they're is a LOD call whoever can answer first. Check on the line throughout the day and make sure people are pushing. Get with your TLs in the morning and see what they are working on. Make sure you have myAlerts on no matter what LOD shift you are - for my store example, weekends get crazy and it TMs usually get close to compliance. As the SR GSTL, my store has a starbucks and the GSTL(s) are cross-trained there.
Early- Open the door in a quick amount of time when the doorbell rings. If your store opens at 7am, you probably won't start until 6:30.