Adjusting Blender’s Settings
Snappy Keys adds timeline cursor snapping to the nearest second, half-second, and keyframes. It also adds keyframe snapping to the nearest second, half-second, or timeline cursor. For this reason it usually makes the most sense to use Snappy Keys with the Show Seconds option in Blender active. You can activate this option by pressing View > Show Seconds in the Timeline or Dopesheet editors. To keep these changes be sure to go to File > Defaults > and press Save Startup File after making these adjustments.
You may also want to adjust the way the seconds are displayed. This can be done by going to Edit > Preferences > Animation > and adjusting the Time Code Style and Minimum Grid Spacing options.
The two best options for the Time Code Style are SMTPE (Compact) and Only Seconds. SMTPE (Compact) displays seconds along with the exact frame of the second. I.E. 00:03:29 would mean that the timeline is 29 frames past the third second. The next frame after that would be 00:04:00 (four seconds). To keep things simple, set this value to Only Seconds.
You can adjust the Minimum Grid Spacing value to ensure that seconds display evenly (1,2,3,4 etc.). Scroll your mouse to zoom while adjusting the Minimum Grid Spacing to find a comfortable range to animate in.