diff --git a/doc/filters.texi b/doc/filters.texi
index 3c2dd2eb90..67892e0afb 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -20782,6 +20782,12 @@ Input frame count.
 @item on
 Output frame count.
 
+@item in_time, it
+The input timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
+
+@item out_time, time, ot
+The output timestamp expressed in seconds.
+
 @item x
 @item y
 Last calculated 'x' and 'y' position from 'x' and 'y' expression
@@ -20820,13 +20826,13 @@ display aspect ratio
 
 @itemize
 @item
-Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
+Zoom in up to 1.5x and pan at same time to some spot near center of picture:
 @example
 zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
 @end example
 
 @item
-Zoom-in up to 1.5 and pan always at center of picture:
+Zoom in up to 1.5x and pan always at center of picture:
 @example
 zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
 @end example
@@ -20836,6 +20842,13 @@ Same as above but without pausing:
 @example
 zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
 @end example
+
+@item
+Zoom in 2x into center of picture only for the first second of the input video:
+@example
+zoompan=z='if(between(in_time,0,1),2,1)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
+@end example
+
 @end itemize
 
 @anchor{zscale}
diff --git a/libavfilter/vf_zoompan.c b/libavfilter/vf_zoompan.c
index 59c9b19ec8..d9d53decf4 100644
--- a/libavfilter/vf_zoompan.c
+++ b/libavfilter/vf_zoompan.c
@@ -38,7 +38,8 @@ static const char *const var_names[] = {
     "on",
     "duration",
     "pduration",
-    "time",
+    "in_time", "it",
+    "out_time", "time", "ot",
     "frame",
     "zoom",
     "pzoom",
@@ -61,7 +62,8 @@ enum var_name {
     VAR_ON,
     VAR_DURATION,
     VAR_PDURATION,
-    VAR_TIME,
+    VAR_IN_TIME, VAR_IT,
+    VAR_TIME, VAR_OUT_TIME, VAR_OT,
     VAR_FRAME,
     VAR_ZOOM,
     VAR_PZOOM,
@@ -155,6 +157,7 @@ static int output_single_frame(AVFilterContext *ctx, AVFrame *in, double *var_va
 {
     ZPContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
+    AVFilterLink *inlink = ctx->inputs[0];
     int64_t pts = s->frame_count;
     int k, x, y, w, h, ret = 0;
     uint8_t *input[4];
@@ -165,7 +168,10 @@ static int output_single_frame(AVFilterContext *ctx, AVFrame *in, double *var_va
     var_values[VAR_PY]    = s->y;
     var_values[VAR_PZOOM] = s->prev_zoom;
     var_values[VAR_PDURATION] = s->prev_nb_frames;
-    var_values[VAR_TIME] = pts * av_q2d(outlink->time_base);
+    var_values[VAR_IN_TIME] = var_values[VAR_IT]  = in->pts == AV_NOPTS_VALUE ?
+        NAN : in->pts * av_q2d(inlink->time_base);
+    var_values[VAR_OUT_TIME] = pts * av_q2d(outlink->time_base);
+    var_values[VAR_TIME] = var_values[VAR_OT] = var_values[VAR_OUT_TIME];
     var_values[VAR_FRAME] = i;
     var_values[VAR_ON] = outlink->frame_count_in;