+File was last accessed \fIn\fR*24 hours ago (if no units are given),
+or \fIn\fR*\fBs\fReconds, \fBm\fRinutes, \fBh\fRours, \fBd\fRays,
+\fBw\fReeks, or \fBy\fRears ago within a margin of error of 24h,
+or smaller if a unit is specified. Multiple units can be specified,
+for example \fB8h20m\fR is equivalent to \fB500m\fR. If multipe units
+are specified, the margin of error is based on the smallest unit used, so
+.B -atime 3d
+has a margin of error of one day, while
+.B -atime 72h
+has a margin of error of one hour.
+.TP
+.BR --blocks | -b
+Blocks allocated by the file is \fIn\fR Kibibytes (if no units are given),
+\fIn\fR 512-byte \fBb\fRlocks, or \fBK\fRibi-, \fBM\fRebi-, \fBG\fRibi-,
+\fBT\fRebi-, \fBP\fRebi-, or \fBE\fRbi-bytes if that suffix is given.