Here are all the residential tariffs you might be on from Synergy/Horizon. In each diagram, the vertical axis is time of day, from midnight to midnight.
Current residential tariffs
These are the residential tariffs you can buy new.
My analysis: don't get the Midday Saver unless you have solar PV and a battery, or your usage in the cheap band outweighs your usage in the expensive band.
If you have a battery, charge it from your PV until 3pm. From 3pm to 9pm, ensure you don't draw power from the grid. It isn't worth charging the battery from the grid at 8 cents and then selling power back to the grid at 10 cents, unless someone other than you is paying for the wear and tear this will cause to the battery. It might be worth charging the battery from PV and selling that to the grid at 10 cents — to find out, do your own maths based on your battery cost and estimated battery wear.
Legacy residential tariffs
You can't buy these new -- the only way you can be on one is if you're already on that one. The horizontal axis is day of week — in some plans, weekends are cheaper.
For Smart Power (SM1), Summer means October to March. Winter means April to September.