diff --git a/afr.js b/afr.js
index a502148..4b4ded8 100644
--- a/afr.js
+++ b/afr.js
@@ -56,47 +56,47 @@ function failure_rate_fullmesh(n, a, f)
 // is that, with k=2, total failure rate doesn't depend on number of peers per OSD,
 // because it gets increased linearly by increased number of peers to fail
 // and decreased linearly by reduced rebalance time.
-function cluster_afr_pgs({ n_hosts, n_drives, afr_drive, capacity, speed, replicas, pgs = 1, osd_rm, degraded_replacement })
+function cluster_afr_pgs({ n_hosts, n_drives, afr_drive, capacity, speed, replicas, pgs = 1, osd_rm, degraded_replacement, down_out_interval = 600 })
 {
     pgs = Math.min(pgs, (n_hosts-1)*n_drives/(replicas-1));
     const resilver_disk = n_drives == 1 || osd_rm ? pgs : (n_drives-1);
-    const disk_heal_time = capacity/(degraded_replacement ? 1 : resilver_disk)/speed/86400/365;
+    const disk_heal_time = (down_out_interval + capacity/(degraded_replacement ? 1 : resilver_disk)/speed)/86400/365;
     return 1 - (1 - afr_drive * (1-(1-(afr_drive*disk_heal_time)**(replicas-1))**pgs)) ** (n_hosts*n_drives);
 }
 
-function cluster_afr_pgs_ec({ n_hosts, n_drives, afr_drive, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, osd_rm, degraded_replacement })
+function cluster_afr_pgs_ec({ n_hosts, n_drives, afr_drive, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, osd_rm, degraded_replacement, down_out_interval = 600 })
 {
     const ec_total = ec_data+ec_parity;
     pgs = Math.min(pgs, (n_hosts-1)*n_drives/(ec_total-1));
     const resilver_disk = n_drives == 1 || osd_rm ? pgs : (n_drives-1);
-    const disk_heal_time = capacity/(degraded_replacement ? 1 : resilver_disk)/speed/86400/365;
+    const disk_heal_time = (down_out_interval + capacity/(degraded_replacement ? 1 : resilver_disk)/speed)/86400/365;
     return 1 - (1 - afr_drive * (1-(1-failure_rate_fullmesh(ec_total-1, afr_drive*disk_heal_time, ec_parity))**pgs)) ** (n_hosts*n_drives);
 }
 
 // Same as above, but also take server failures into account
-function cluster_afr_pgs_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, replicas, pgs = 1, osd_rm, degraded_replacement })
+function cluster_afr_pgs_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, replicas, pgs = 1, osd_rm, degraded_replacement, down_out_interval = 600 })
 {
     const otherhosts = Math.min(pgs, (n_hosts-1)/(replicas-1));
     pgs = Math.min(pgs, (n_hosts-1)*n_drives/(replicas-1));
     const resilver_disk = n_drives == 1 || osd_rm ? pgs : (n_drives-1);
     const pgh = Math.min(pgs*n_drives, (n_hosts-1)*n_drives/(replicas-1));
-    const disk_heal_time = capacity/(degraded_replacement ? 1 : resilver_disk)/speed/86400/365;
-    const host_heal_time = n_drives*capacity/pgs/speed/86400/365;
+    const disk_heal_time = (down_out_interval + capacity/(degraded_replacement ? 1 : resilver_disk)/speed)/86400/365;
+    const host_heal_time = (down_out_interval + n_drives*capacity/pgs/speed)/86400/365;
     const p1 = ((afr_drive+afr_host*pgs/otherhosts)*host_heal_time);
     const p2 = ((afr_drive+afr_host*pgs/otherhosts)*disk_heal_time);
     return 1 - ((1 - afr_host * (1-(1-p1**(replicas-1))**pgh)) ** n_hosts) *
         ((1 - afr_drive * (1-(1-p2**(replicas-1))**pgs)) ** (n_hosts*n_drives));
 }
 
-function cluster_afr_pgs_ec_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, osd_rm, degraded_replacement })
+function cluster_afr_pgs_ec_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, osd_rm, degraded_replacement, down_out_interval = 600 })
 {
     const ec_total = ec_data+ec_parity;
     const otherhosts = Math.min(pgs, (n_hosts-1)/(ec_total-1));
     pgs = Math.min(pgs, (n_hosts-1)*n_drives/(ec_total-1));
     const resilver_disk = n_drives == 1 || osd_rm ? pgs : (n_drives-1);
     const pgh = Math.min(pgs*n_drives, (n_hosts-1)*n_drives/(ec_total-1));
-    const disk_heal_time = capacity/(degraded_replacement ? 1 : resilver_disk)/speed/86400/365;
-    const host_heal_time = n_drives*capacity/pgs/speed/86400/365;
+    const disk_heal_time = (down_out_interval + capacity/(degraded_replacement ? 1 : resilver_disk)/speed)/86400/365;
+    const host_heal_time = (down_out_interval + n_drives*capacity/pgs/speed)/86400/365;
     const p1 = ((afr_drive+afr_host*pgs/otherhosts)*host_heal_time);
     const p2 = ((afr_drive+afr_host*pgs/otherhosts)*disk_heal_time);
     return 1 - ((1 - afr_host * (1-(1-failure_rate_fullmesh(ec_total-1, p1, ec_parity))**pgh)) ** n_hosts) *
diff --git a/main.js b/main.js
index 8913591..6dbd28f 100644
--- a/main.js
+++ b/main.js
@@ -67,7 +67,7 @@ class Calc extends preact.Component
     format4 = (n) =>
     {
         let p = Math.abs(n-(n|0)), m = 10000;
-        while (p != 0 && p < 0.1)
+        while (n < 1 && p != 0 && p < 0.1)
         {
             p = p*10;
             m = m*10;