> For the complete documentation index, see [llms.txt](https://orbcity.gitbook.io/orbcity/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://orbcity.gitbook.io/orbcity/building/upgrading-system/level-up/time.md).

# Time

$$
Level~~up\_{time}=t\_l~~\*~~tier~~and\~level\_{t}
$$

$$
t\_l=7\~days
$$

#### tier\_t & level\_t

| Lev  | common | rare   | epic   | unique | legendary |
| ---- | ------ | ------ | ------ | ------ | --------- |
| 1->2 | 0.3000 | 0.5625 | 1.4766 | 5.5371 | 29.0698   |
| 2->3 | 0.4500 | 0.8438 | 2.2148 | 8.3057 | 43.6047   |

Building owners can use time coupons to reduce the time it takes to level up their building NFTs.

#### Level Up Time (d)

| Lev  | common | rare    | epic      | unique    | legendary |
| ---- | ------ | ------- | --------- | --------- | --------- |
| 1->2 | 2.1    | 3.9375  | 10.33598  | 38.759766 | 203.48877 |
| 2->3 | 3.15   | 5.90625 | 15.503906 | 58.139648 | 305.23315 |

{% hint style="info" %}
The value of **t\_l** may be adjusted by governance.
{% endhint %}

{% hint style="info" %}
**Note: Please note that all figures are subject to change by governance.**
{% endhint %}